Change settings area to be separated into categories in admin UI

[Gargron]

The settings are split into:

• Branding
• About
• Registrations
• Discovery
• Content retention
• Appearance

Furthermore:

• "Server description" is removed, "Short server description" takes its place
• Character limit of 200 on the new "Server description"
• Removed the following settings (for limited applicability and not fitting into any other category neatly):
  • Publish aggregate statistics about user activity in the API
  • Publish list of discovered servers in the API
  • Show sensitive media in OpenGraph previews
• Extended description now supports Markdown syntax

Screenshots

[ClearlyClaire]

One thing I missed when reviewing and that is not mentioned in the PR comment was that the setting to disable indexing by default has been removed. Is it an oversight? If not, why was it removed?

[Gargron]

Some things happened in the last 19 days that kind of make me blank on my exact thought process, but trying to recreate it now, I probably thought that it's strange to have an option for overriding a default user preference. If admins want their entire site to not be indexed, that option didn't do that, and then users would be able to override it on their profiles anyway. Would you like me to add an option that ensures that all pages have a noindex tag on them?

[ClearlyClaire]

it's strange to have an option for overriding a default user preference

I guess, but it's also something that many feel strongly should not be opt-out.

If admins want their entire site to not be indexed, that option didn't do that, and then users would be able to override it on their profiles anyway. Would you like me to add an option that ensures that all pages have a noindex tag on them?

I don't think that's what admins want, I think it's more about it being opt-out rather than opt-in. But I guess such a setting could be a good thing too. Honestly I'm not sure what the best course of action would be.