Group related admin settings together

[Nutomic]

In the user settings we already have related items grouped together, for example change password or settings import/export. This makes it easier to find a specific item.

But the main site settings are all in a single list, without any clear order. We should add some groups or sections like this:

• Description
  • Name, icon, banner, summary, sidebar, legal (or call it rules), content warning, private instance
• Registration
  • Open/Closed, captcha, registration application
• Votes
• Sort defaults
  • Listing type, post sort type etc
• Content
  • Slur filter, url blocks, languages
• Notifications
  • All checkboxes related to email and notifications

Also "federation enabled" should be moved to the instances tab. If federation is disabled, all settings for instance allowlist/blocklist should be hidden.

[dessalines]

Part of the reason for that separation, is just based on the API action, with a single save button.

We could have several sections (or tabs) like you're saying, but they would effectively call the same save API action. Its probably a good idea tho, just for organizing purposes.