chore: simplify plugin readmes, changelogs and manifest descriptions

plugins/totp/README.md

@@ -0,0 +1,19 @@
+# TOTP
+
+Ask for a code from an authenticator app after signing in, with backup codes in case you lose your phone.
+
+## Features
+
+- Ask for a code from an authenticator app after signing in.
+- Backup codes you can download and use if you lose your phone.
+- Add more than one device.
+
+## Development
+
+```bash
+npm run build      # build into dist/
+npm run test       # run this plugin's tests
+npm run typecheck  # type-check this plugin
+```
+
+See `packages/plugin-sdk/ARCHITECTURE.md` for the plugin contract.