[docs] Migrate Module_visibility_and_display

[sarjona]

The URL of the page on https://docs.moodle.org/dev/

https://docs.moodle.org/dev/Module_visibility_and_display

Is this documentation specific to a Moodle version?

Yes

What location would you suggest in the new docs?

What about docs/apis/plugintypes/mod/visibility.md ?

[abdnafees]

Changes have been pushed. Please review.