[Migrate]: Post Types Activities

[imath]

Link to the existing BP Codex page.

https://codex.buddypress.org/plugindev/post-types-activities/

What needs to be done?

I believe this help resource should be almost ready as we haven't improved / updated this feature that much since it was introduced.

Handbook to migrate the page in

buddypress/docs/developer

Tasks to accomplish

• This task has been added to the "Todo" panel of the Documentation project.
• The corresponding line of the data/README.md Pages list has been marked as "Migrate issue/task created".
• 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.
• 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.