message: Add a step about running AppImage file.
diff: @@ -46,6 +46,7 @@ As with macOS's `brew` install, the AUR may also be outdated. To install the lat
  * `cd upterm`
  * `npm install`
  * `npm run pack`
  +* Run the `*.AppImage` file located in the `dist/` subdirectory.
  ###### Windows
  