v1.3.1-rc.1

Full Changelog

• Upgrade to JS SDK 2.3.0-rc.1 and React SDK 1.5.0-rc.1
• Update from Weblate
  #10436
• Describe our existing features better in documentation
  #10418
• Upgrade to Electron 5
  #10392
• Remove edits and reactions feature flags from docs and config
  #10363
• Cachebust config file requests
  #10349
• Convert install-app-deps to subcommand
  #10334
• Add riot.im configuration files
  #10327
• Require descriptions in mxSendRageshake and remove infinite loop in issue
  templates
  #10321
• Remove unused disable_identity_server config flag
  #10322
• Verify i18n in CI
  #10320