Remove no-longer-relevant text from CHEATSHEET.rst

Once my other PRs are merged, I think we'll have finished doing
everything listed in the CHEATSHEET setup list, so we can delete it.

CHEATSHEET.rst

@@ -1,41 +1,3 @@
-Finishing setting up your project
-=================================
-
-Thanks for using cookiecutter-trio! This is your project now; you can
-customize it however you like. Here's some reminders of things you
-might want to do to get started:
-
-* Check this into source control (``git init .; git add .; git
-  commit -m "Initial commit"``)
-
-* Add a CODE_OF_CONDUCT.md
-
-* Add a CONTRIBUTING.md
-
-* Search the source tree for COOKIECUTTER-TRIO-TODO to find other
-  places to fill in.* Enable `Read the Docs <https://readthedocs.org>`__. (Note: this
-  project contains a ``.readthedocs.yml`` file that should be enough
-  to get things working.)
-
-* Set up continuous integration: Currently, this project is set up to
-  test on Linux and MacOS using Travis, on Windows using Appveyor, and
-  to test on PyPy.
-
-  If that's what you want, then go to Travis and Appveyor and enable
-  testing for your repo.
-
-  If that's not what you want, then you can trim the list by modifying
-  (or deleting) ``.travis.yml``, ``.appveyor.yml``, ``ci/travis.sh``.
-
-* Enable `Codecov <https://codecov.io>`__ for your repo.
-
-* File bugs or pull requests on `cookiecutter-trio
-  <https://github.com/python-trio/cookiecutter-trio>`__ reporting any
-  problems or awkwardness you ran into (no matter how small!)
-
-* Delete this checklist once it's no longer useful
-
-
 Tips
 ====