Missing API documentation

[schiessle]

We have here quite some API documentation but it seems like some important parts like activities or comments are missing: https://docs.nextcloud.com/server/17/developer_manual/client_apis/index.html

[schiessle]

cc @tobiasKaminsky as discussed

[tobiasKaminsky]

Comments: nextcloud/server#7315 (comment)
Activity: https://github.com/nextcloud/activity/blob/master/docs/endpoint-v2.md

This should be both in docs.nc.c

[jospoortvliet]

Comments: nextcloud/server#7315 (comment)
Activity: https://github.com/nextcloud/activity/blob/master/docs/endpoint-v2.md

This should be both in docs.nc.c

Indeed, it should. Here's a simple PR:
#1968

Taking the comments comment into the docs and linking to the activities. pls check if I put things in the right place...

[MorrisJobke]

Fixed in #1968