Merge commit '4ad1c5aa7174e5cef4ba9608a44429916a119bee' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Upstream has updated their README, we have a completely different one.
  Kept ours.
- `config/initializers/content_security_policy.rb`:
  Upstream has updated their development CSPs, while we disable CSPs in
  the development environment.
  Kept our version.

config/webpacker.yml

@@ -59,7 +59,7 @@ development:
   # Reference: https://webpack.js.org/configuration/dev-server/
   dev_server:
     https: false
-    host: localhost
+    host: 0.0.0.0
     port: 3035
     public: localhost:3035
     hmr: false