Extend dev guide for collection testing and collection hacking

[felixfontein]

SUMMARY

This extends the dev guide with details for working with collections:

1. running ansible-test in collections;
2. hacking collections (cloning them and using the cloned ones).

Also contains three tiny only somewhat related improvements:

1. document new bot commands /rebuild and /rebuild_failed (141d2c2), CC @jctanner;
2. fix/improve first paragraph of BOTMETA.yml docs for collections (55ae0b5);
3. update list of Python versions for compile tests (a608b58).

CC @gundalow @maxamillion @mattclay

ISSUE TYPE

• Docs Pull Request

COMPONENT NAME

docs/docsite/rst/dev_guide/developing_collections.rst
docs/docsite/rst/dev_guide/testing_compile.rst
docs/docsite/rst/dev_guide/testing.rst

[mattclay]

I'd omit the --color option, as it's normally auto-detected for interactive use. It should only be needed when piping stdout or on CI systems which do not report stdout as a TTY.

Suggested change

	ansible-test sanity --docker default --color -v
	ansible-test sanity --docker default -v

The same applies to the other examples below.

I'd also consider using --docker instead of --docker default (but with a note mentioning that using a non-option after it will be seen as a container name).

[felixfontein]

I'll remove --color then.

I included default after --docker to avoid that when people remove --color -v, it suddenly reports "strange" errors when they list an explicit target.

[maxamillion]

This is great, thank you @felixfontein!! 👍

[odyssey4me]

Awesome documentation addition, thank you!

[felixfontein]

Suggested change

For collections hosted in the ``ansible_collections`` GitHub org, create a branch and commit your changes on the branch. When you are done (remember to add tests, see :ref:`testing_collections`), push your changes to your fork of the collection and create a Pull Request. For other collections, especially for collections not hosted on GitHub, check the ``README.md`` of the collection for information on contributing to it.

For collections hosted in the ``ansible-collections`` GitHub org, create a branch and commit your changes on the branch. When you are done (remember to add tests, see :ref:`testing_collections`), push your changes to your fork of the collection and create a Pull Request. For other collections, especially for collections not hosted on GitHub, check the ``README.md`` of the collection for information on contributing to it.

It's https://github.com/ansible-collections/ with a dash.

[felixfontein]

Thanks everyone for reviewing and your comments, and especially @acozine for heavily improving it!