Merge commit '757d7c73c0ca3750ac9e74a7e962f71c535a7bd0' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Upstream updated its README, we have a completely different one.
  Kept ours.
- `yarn.lock`:
  Upstream changed from yarn 1 to yarn 4, but we had some different
  dependencies.
  Updated to yarn 4 and re-added our dependencies.

jest.config.js

@@ -17,6 +17,8 @@ const config = {
     '!app/javascript/mastodon/service_worker/entry.js',
     '!app/javascript/mastodon/test_setup.js',
   ],
+  // Those packages are ESM, so we need them to be processed by Babel
+  transformIgnorePatterns: ['/node_modules/(?!(redent|strip-indent)/)'],
   coverageDirectory: '<rootDir>/coverage',
   moduleDirectories: ['<rootDir>/node_modules', '<rootDir>/app/javascript'],
   moduleNameMapper: {