Maksim authored May 06, 2019 and lain committed May 06, 2019

Modified-by: Maksim Pechnikov <parallel588@gmail.com>

Fix leaking private configuration parameters in Mastodon and Twitter APIs, and add new configuration parameters to Mastodon API

This patch:
- Fixes `rights` in twitterapi ignoring `show_role`
- Fixes exposing default scope of the user to anyone in Mastodon API
- Extends Mastodon API to be able to show and set `no_rich_text`, `default_scope`, `hide_follows`, `hide_followers`, `hide_favorites` (requested by the FE in #674)

Sorry in advance for 500 line one commit diff, I should have split it up to separate MRs

I understand that this change is quite unreadable and hard to review, sorry for forgetting to do atomic commits. This patch does not change too much content wise, it just
* Gets everything from gitlab wiki
* Removes some specific gitlab hacks
* Formats all documentation file names to be in snake case so they look the same way as our code does

This is to make it easier for the frontends to handle domain.com/users/nickname
urls.

Add a section on how to identify a pleroma instance, clarify that post upload limit is not capped too

Remove a limit on attachments in Mastodon API and document the changes in responses from vanilla mastodon