[Migrate]: Participate and Contribute

[imath]

Link to the existing BP Codex page.

https://codex.buddypress.org/participate-and-contribute/

What needs to be done?

Almost ready to be migrated as the contributor doc's homepage !

Handbook to migrate the page in

buddypress/docs/contributor

Tasks to accomplish

• [x] This task has been added to the "Todo" panel of the Documentation project.
• [x] The corresponding line of the data/README.md Pages list has been marked as "Migrate issue/task created".
• [x] A PR has been submitted to the BuddyPress GH repository, it has been linked to this issue/task & the task was moved to the "In progress" panel of the Documentation project.
• [x] The PR has been converted to a SVN patch and committed to the BuddyPress SVN repository & the task was moved to the "Done" panel of the Documentation project.