Improve role argspec documentation

[felixfontein]

Ref: https://forum.ansible.com/t/clarify-documentation-argument-specs-yml-author-list-or-string/3870

[jms1voalte]

Nice, this fixes a couple of other problems I had noticed as well.

Thanks.

[oraNod]

Thanks @felixfontein !

[patchback]

Backport to stable-2.15: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply be66e62 on top of patchback/backports/stable-2.15/be66e621614c40de6759095a1a9bb8b37a14fcf1/pr-1126

Backporting merged PR #1126 into devel

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/ansible/ansible-documentation.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/stable-2.15/be66e621614c40de6759095a1a9bb8b37a14fcf1/pr-1126 upstream/stable-2.15

4. Now, cherry-pick PR Improve role argspec documentation #1126 contents into that branch:

   $ git cherry-pick -x be66e621614c40de6759095a1a9bb8b37a14fcf1

   If it'll yell at you with something like fatal: Commit be66e621614c40de6759095a1a9bb8b37a14fcf1 is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x be66e621614c40de6759095a1a9bb8b37a14fcf1

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Improve role argspec documentation #1126 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/stable-2.15/be66e621614c40de6759095a1a9bb8b37a14fcf1/pr-1126

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[felixfontein]

@jms1voalte @oraNod thanks for reviewing!

[patchback]

Backport to stable-2.16: 💚 backport PR created

✅ Backport PR branch: patchback/backports/stable-2.16/be66e621614c40de6759095a1a9bb8b37a14fcf1/pr-1126

Backported as #1127

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.