Add contributing doc and DCO file (#88)

* Add contributing doc and DCO file

Signed-off-by: Kevin Lingerfelt <kl@buoyant.io>

* Fix small typos

Signed-off-by: Kevin Lingerfelt <kl@buoyant.io>

Author: klingerf

CONTRIBUTING.md

@@ -0,0 +1,103 @@
+# Contributing to Conduit #
+
+:balloon: Thanks for your help improving the project!
+
+## Getting Help ##
+
+If you have a question about Conduit or have encountered problems using it,
+start by [asking a question in the forums][discourse] or join us in the
+[#conduit Slack channel][slack].
+
+## Certificate of Origin ##
+
+By contributing to this project you agree to the Developer Certificate of
+Origin (DCO). This document was created by the Linux Kernel community and is a
+simple statement that you, as a contributor, have the legal right to make the
+contribution. See the [DCO](DCO) file for details.
+
+In practice, just add a line to every git commit message:
+
+```
+Signed-off-by: Jane Smith <jane.smith@example.com>
+```
+
+Use your real name (sorry, no pseudonyms or anonymous contributions).
+
+If you set your `user.name` and `user.email` git configs, you can sign your
+commit automatically with `git commit -s`.
+
+## Submitting a Pull Request ##
+
+Do you have an improvement?
+
+1. Submit an [issue][issue] describing your proposed change.
+2. We will try to respond to your issue promptly.
+3. Fork this repo, develop and test your code changes. See the project's [README](README.md) for further information about working in this repository.
+4. Submit a pull request against this repo's `master` branch.
+5. Your branch may be merged once all configured checks pass, including:
+    - 2 code review approvals, at least 1 of which is from a [runconduit organization member][members].
+    - The branch has passed tests in CI.
+
+## Committing ##
+
+We prefer squash or rebase commits so that all changes from a branch are
+committed to master as a single commit. All pull requests are squashed when
+merged, but rebasing prior to merge gives you better control over the commit
+message.
+
+### Commit messages ###
+
+Finalized commit messages should be in the following format:
+
+```
+Subject
+
+Problem
+
+Solution
+
+Validation
+
+Fixes #[GitHub issue ID]
+```
+
+#### Subject ####
+
+- one line, <= 50 characters
+- describe what is done; not the result
+- use the active voice
+- capitalize first word and proper nouns
+- do not end in a period — this is a title/subject
+- reference the GitHub issue by number
+
+##### Examples #####
+
+```
+bad: server disconnects should cause dst client disconnects.
+good: Propagate disconnects from source to destination
+```
+
+```
+bad: support tls servers
+good: Introduce support for server-side TLS (#347)
+```
+
+#### Problem ####
+
+Explain the context and why you're making that change.  What is the problem
+you're trying to solve? In some cases there is not a problem and this can be
+thought of as being the motivation for your change.
+
+#### Solution ####
+
+Describe the modifications you've made.
+
+#### Validation ####
+
+Describe the testing you've done to validate your change.  Performance-related
+changes should include before- and after- benchmark results.
+
+[discourse]: https://discourse.linkerd.io/c/conduit
+[issue]: https://github.com/runconduit/conduit/issues/new
+[members]: https://github.com/orgs/runconduit/people
+[slack]: http://slack.linkerd.io/

DCO

@@ -0,0 +1,37 @@
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.