Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Our README.md files are completely different. Discarded upstream changes.
- `app/javascript/core/admin.js`:
  Updating rails-ujs, no real conflict, but a comment to close to changed
  code. Various glitch-soc-only files have been updated to match those changes,
  though.
- `package.json`:
  No real conflict, just an additional dependency in glitch-soc that was too
  close to something updated upstream. Took upstream's changes.

app/javascript/core/admin.js

@@ -1,6 +1,6 @@
 //  This file will be loaded on admin pages, regardless of theme.
 
-import { delegate } from 'rails-ujs';
+import { delegate } from '@rails/ujs';
 import ready from '../mastodon/ready';
 
 const batchCheckboxClassName = '.batch-checkbox input[type="checkbox"]';

app/javascript/core/public.js

@@ -3,7 +3,7 @@
 import createHistory from 'history/createBrowserHistory';
 import ready from '../mastodon/ready';
 
-const { delegate } = require('rails-ujs');
+const { delegate } = require('@rails/ujs');
 const { length } = require('stringz');
 
 delegate(document, '.webapp-btn', 'click', ({ target, button }) => {

app/javascript/core/settings.js

@@ -1,7 +1,7 @@
 //  This file will be loaded on settings pages, regardless of theme.
 
 import escapeTextContentForBrowser from 'escape-html';
-const { delegate } = require('rails-ujs');
+const { delegate } = require('@rails/ujs');
 import emojify from '../mastodon/features/emoji/emoji';
 
 delegate(document, '#account_display_name', 'input', ({ target }) => {