Merge documentation and benchmarks from metapackage

This cross-repository merge unifies the documentation, benchmarks and
code of conduct from the metapackage into Qiskit/Terra's build.

There are very non-trivial merge conflicts that have been resolved by
this commit.  The summary is:

- `CODE_OF_CONDUCT.md`: taken directly from the metapackage's version.
- `docs/conf.py`: strongly unified, albeit without the translations
  components that are added in a separate commit.
- `docs/index.rst`: taken almost verbatim from the metapackage.  All the
  API documentation RST files on Terra are moved to `docs/apidoc`
  (without the trailing 's') to match the metapackage expectation, so
  the URLs of built documentation will not change.
- `docs/release_notes.rst`: The metapackage's version is renamed to
  `docs/legacy_release_notes.rst`, given a small introductory header,
  and made an orphan linked only from a _new_ `docs/release_notes.rst`
  that uses `reno`.
- `docs/tutorials.rst`: Mostly these were the same already.  Updated to
  include Qiskit/Terra's correction that it's not an orphan, and contain
  the metapackage's extra intro tutorial.
- `docs/apidoc/terra.rst`: renamed to `docs/apidoc/index.rst` and retitled
  to be correctly just "API Documentation".
- `requirements-dev.txt`: the version of the Sphinx theme is bumped to 1.14
  to match the metapackage expectation.

CODE_OF_CONDUCT.md

@@ -1,9 +1,114 @@
-<!-- Copyright Contributors to the Qiskit project. -->
-
 # Code of Conduct
-All members of this project agree to adhere to the Qiskit Code of Conduct listed at [https://github.com/Qiskit/qiskit/blob/master/CODE_OF_CONDUCT.md](https://github.com/Qiskit/qiskit/blob/master/CODE_OF_CONDUCT.md)
 
-----
+## Our Pledge
+
+The Qiskit Community is dedicated to our values of treating every individual
+with respect and dignity. In the interest of fostering an open and welcoming
+environment, all participants, including attendees, speakers, sponsors,
+volunteers, online contributors, and IBM employees are expected to show
+courtesy for each other and our community by creating a harassment-free
+experience for everyone, regardless of age, personal appearance, disability,
+ethnicity, gender identity and expression, body size, level of experience,
+nationality, race, religion, caste, or sexual identity and orientation.
+Expected behavior applies to both online and offline engagement within the
+Qiskit Community.
+
+## Scope
+
+The purpose of this Code of Conduct is to define and enforce the values and
+conduct of contributors and participants in the Qiskit open source community.
+The Code of Conduct applies both within project spaces and in public spaces
+when an individual is engaging with the Qiskit open source community. Examples
+include attending a Qiskit event, contributing to online projects, commentary
+on Slack, or representing a project or community, including using an official
+project e-mail address, posting via an official social media account, or
+acting as an appointed representative at an online or offline event.
+Representation of a project may be further defined and clarified by project
+maintainers.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+- Using welcoming and inclusive language
+- Being respectful of differing viewpoints, experiences, and cultures
+- Gracefully accepting constructive criticism
+- Focusing on what is best for the community
+- Showing empathy towards other community members
+- Being mindful of your surroundings and your fellow participants and listening
+  to others
+- Valuing the contributions of all participants
+- Engaging in collaboration before conflict
+- Pointing out unintentionally racist, sexist, casteist, or biased comments and
+  jokes made by community members when they happen
+
+Examples of unacceptable behavior by participants, even when presented as
+"ironic" or "joking," include:
+
+- The use of sexualized language or imagery and unwelcome physical contact,
+  sexual attention, or advances
+- Trolling, insulting/derogatory comments, and personal or political attacks
+- Public or private harassment, including offensive or degrading language
+- Publishing others' private information, such as a physical or electronic
+  address, without explicit permission. This includes any sort of "outing" of
+  any aspect of someone's identity without their consent.
+- "Doxxing," Publishing screenshots or quotes, especially from identity slack
+  channels, private chat, or public events, without all quoted users' explicit
+  consent.
+- Engaging in spamming activities, such as repeatedly sending unsolicited messages, LLMs (Large Language Models) output, advertisements, or promotional content to community members without previous IBM authorization.
+- Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Responsibilities & Enforcement
+
+The entire Qiskit community is responsible for upholding the terms of the Code
+of Conduct in Qiskit Community events and spaces and reporting violations if
+they see them. The internal Qiskit team at IBM is ultimately responsible for
+clarifying the standards of acceptable behavior and enforcement, and is expected
+to take appropriate and fair corrective action in response to any instances of
+unacceptable behavior.
+
+If a participant or contributor engages in negative or harmful behavior, IBM
+will take any action they deem appropriate, including but not limited to
+issuing warnings, expulsion from an event with no refund, deleting comments,
+permanent banning from future events or online community, or calling local law
+enforcement. IBM has the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, or to temporarily or permanently ban any
+contributor or participant for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+If you see a Code of Conduct violation:
+
+1. If you feel comfortable, let the person know that what they did is not
+   appropriate and ask them to stop and/or edit or delete their message(s) or
+   comment(s).
+2. If the person does not immediately stop the behavior or correct the issue,
+   or if you're uncomfortable speaking up, flag a moderator and, if appropriate,
+   fill out the anonymous
+   [Code of Conduct violation form](https://airtable.com/shrl5mEF4Eun1aIDm).
+3. The Qiskit Community will open an investigation upon receiving your form
+   entry. When reporting, please include any relevant details, links,
+   screenshots, context, or other information that may be used to better
+   understand and resolve the situation.
+4. If the code of conduct violation occurs at an event and requires immediate
+   response or contains a concern about an individual attending an upcoming
+   event, contact the event's on-call Code of Conduct point of contact listed
+   in the event specific code of conduct document. If you don't feel comfortable
+   speaking to the point of contact in person, fill out a Code of Conduct
+   violation form entry and include the details of the event so that the Code of
+   Conduct enforcement board can contact the event's on-call Code of Conduct
+   point of contact.
+5. If an IBM employee witnesses a Code of Conduct violation at any time, such as
+   at events, in a Slack channel, or open source forums, it is their
+   responsibility to file a Code of Conduct violation report.
 
-License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/),
-Copyright Contributors to Qiskit.
+This Code of Conduct does not supersede existing IBM corporate policies, such as
+the IBM Business Conduct Guidelines and IBM Business Partner Code of Conduct.
+IBM employees must follow IBM's Business Conduct Guidelines. IBM's business
+partners must follow the IBM Business Partner Code of Conduct. IBM employees
+concerned with a fellow IBMer's behavior should follow IBM's own internal HR
+reporting protocols, which include engaging the offending IBMer's manager and
+involving IBM Concerns and Appeals. IBM employees concerned with an IBM
+business partner's behavior should notify tellibm@us.ibm.com.

asv.conf.json

@@ -0,0 +1,172 @@
+{
+    // The version of the config file format.  Do not change, unless
+    // you know what you are doing.
+    "version": 1,
+
+    // The name of the project being benchmarked
+    "project": "qiskit-terra",
+
+    // The project's homepage
+    "project_url": "https://qiskit.org",
+
+    // The URL or local path of the source code repository for the
+    // project being benchmarked
+    "repo": "https://github.com/Qiskit/qiskit-terra.git",
+
+    // The Python project's subdirectory in your repo.  If missing or
+    // the empty string, the project is assumed to be located at the root
+    // of the repository.
+    // "repo_subdir": "",
+
+    // Customizable commands for building, installing, and
+    // uninstalling the project. See asv.conf.json documentation.
+    //
+    "install_command": [
+        "return-code=any python -c \"import shutil; shutil.rmtree('{build_dir}/build')\"",
+        "return-code=any python -c \"import shutil; shutil.rmtree('{build_dir}/qiskit_terra.egg-info')\"",
+        "python -mpip install seaborn",
+        "python -mpip install pygments",
+        "python -mpip install {wheel_file}",
+        "python -mpip install -U qiskit-experiments==0.3.0",
+        "python -mpip install -U python-constraint"
+      ],
+    "uninstall_command": [
+        "return-code=any python -mpip uninstall -y {project}",
+        "return-code=any python -mpip uninstall -y qiskit-experiments"
+    ],
+    "build_command": [
+        "pip install -U Cython setuptools-rust",
+        "python setup.py build_rust --release",
+        "PIP_NO_BUILD_ISOLATION=false python -mpip wheel --no-deps --no-index -w {build_cache_dir} {build_dir}"
+    ],
+
+    // List of branches to benchmark. If not provided, defaults to "master"
+    // (for git) or "default" (for mercurial).
+    "branches": ["main"], // for git
+    // "branches": ["default"],    // for mercurial
+
+    // The DVCS being used.  If not set, it will be automatically
+    // determined from "repo" by looking at the protocol in the URL
+    // (if remote), or by looking for special directories, such as
+    // ".git" (if local).
+    "dvcs": "git",
+
+    // The tool to use to create environments.  May be "conda",
+    // "virtualenv" or other value depending on the plugins in use.
+    // If missing or the empty string, the tool will be automatically
+    // determined by looking for tools on the PATH environment
+    // variable.
+    "environment_type": "virtualenv",
+
+    // timeout in seconds for installing any dependencies in environment
+    // defaults to 10 min
+    //"install_timeout": 600,
+
+    // the base URL to show a commit for the project.
+    "show_commit_url": "http://github.com/Qiskit/qiskit-terra/commit/",
+
+    // The Pythons you'd like to test against.  If not provided, defaults
+    // to the current version of Python used to run `asv`.
+    "pythons": ["3.7", "3.8", "3.9", "3.10"],
+
+    // The list of conda channel names to be searched for benchmark
+    // dependency packages in the specified order
+    // "conda_channels": ["conda-forge", "defaults"]
+
+    // The matrix of dependencies to test.  Each key is the name of a
+    // package (in PyPI) and the values are version numbers.  An empty
+    // list or empty string indicates to just test against the default
+    // (latest) version. null indicates that the package is to not be
+    // installed. If the package to be tested is only available from
+    // PyPi, and the 'environment_type' is conda, then you can preface
+    // the package name by 'pip+', and the package will be installed via
+    // pip (with all the conda available packages installed first,
+    // followed by the pip installed packages).
+    //
+    // "matrix": {
+    //     "numpy": ["1.6", "1.7"],
+    //     "six": ["", null],        // test with and without six installed
+    //     "pip+emcee": [""],   // emcee is only available for install with pip.
+    // },
+
+    // Combinations of libraries/python versions can be excluded/included
+    // from the set to test. Each entry is a dictionary containing additional
+    // key-value pairs to include/exclude.
+    //
+    // An exclude entry excludes entries where all values match. The
+    // values are regexps that should match the whole string.
+    //
+    // An include entry adds an environment. Only the packages listed
+    // are installed. The 'python' key is required. The exclude rules
+    // do not apply to includes.
+    //
+    // In addition to package names, the following keys are available:
+    //
+    // - python
+    //     Python version, as in the *pythons* variable above.
+    // - environment_type
+    //     Environment type, as above.
+    // - sys_platform
+    //     Platform, as in sys.platform. Possible values for the common
+    //     cases: 'linux2', 'win32', 'cygwin', 'darwin'.
+    //
+    // "exclude": [
+    //     {"python": "3.2", "sys_platform": "win32"}, // skip py3.2 on windows
+    //     {"environment_type": "conda", "six": null}, // don't run without six on conda
+    // ],
+    //
+    // "include": [
+    //     // additional env for python2.7
+    //     {"python": "2.7", "numpy": "1.8"},
+    //     // additional env if run on windows+conda
+    //     {"platform": "win32", "environment_type": "conda", "python": "2.7", "libpython": ""},
+    // ],
+
+    // The directory (relative to the current directory) that benchmarks are
+    // stored in.  If not provided, defaults to "benchmarks"
+    "benchmark_dir": "test/benchmarks",
+
+    // The directory (relative to the current directory) to cache the Python
+    // environments in.  If not provided, defaults to "env"
+    "env_dir": ".asv/env",
+
+    // The directory (relative to the current directory) that raw benchmark
+    // results are stored in.  If not provided, defaults to "results".
+    "results_dir": ".asv/results",
+
+    // The directory (relative to the current directory) that the html tree
+    // should be written to.  If not provided, defaults to "html".
+    // "html_dir": "html",
+
+    // The number of characters to retain in the commit hashes.
+    // "hash_length": 8,
+
+    // `asv` will cache results of the recent builds in each
+    // environment, making them faster to install next time.  This is
+    // the number of builds to keep, per environment.
+    // "build_cache_size": 2,
+
+    // The commits after which the regression search in `asv publish`
+    // should start looking for regressions. Dictionary whose keys are
+    // regexps matching to benchmark names, and values corresponding to
+    // the commit (exclusive) after which to start looking for
+    // regressions.  The default is to start from the first commit
+    // with results. If the commit is `null`, regression detection is
+    // skipped for the matching benchmark.
+    //
+    // "regressions_first_commits": {
+    //    "some_benchmark": "352cdf",  // Consider regressions only after this commit
+    //    "another_benchmark": null,   // Skip regression detection altogether
+    // },
+
+    // The thresholds for relative change in results, after which `asv
+    // publish` starts reporting regressions. Dictionary of the same
+    // form as in ``regressions_first_commits``, with values
+    // indicating the thresholds.  If multiple entries match, the
+    // maximum is taken. If no entry matches, the default is 5%.
+    //
+    // "regressions_thresholds": {
+    //    "some_benchmark": 0.01,     // Threshold of 1%
+    //    "another_benchmark": 0.5,   // Threshold of 50%
+    // },
+}

docs/apidocs/terra.rst → docs/apidoc/index.rst

@@ -1,8 +1,8 @@
 .. module:: qiskit
 
-==========================
-Qiskit Terra API Reference
-==========================
+=============
+API Reference
+=============
 
 .. toctree::
    :maxdepth: 1