Create contributing to ros (backport #6918)

[mergify]

3di | New 'Contributing to ROS' article and updated 'Contact' article

This is draft pull request. Both of the articles included in this pull request are dependent on the ToC structure being reoganized.

Contributing to ROS

• Created a new article about the ways in which the community can contribute to ROS.

• Used Geoff's notes about the priority for and detail of what’s important for each type of contribution.

Contact

• Updated the article to fit with the new 'Contributing to ROS' article.

Related to: #6828

Did you use Generative AI?

No

Additional Information

Documentation updates from 3di Information Solutions, agreed with Geoff and Tully.

Label

Please add backport-lyrical.

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This is an automatic backport of pull request #6918 done by Mergify.

[mergify]

Cherry-pick of ca528b8 has failed:

On branch mergify/bp/lyrical/pr-6918
Your branch is up to date with 'origin/lyrical'.

You are currently cherry-picking commit ca528b8.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	new file:   source/Contributing-To-ROS.rst
	modified:   source/index.rst

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   source/Contact.rst

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally