https://stackoverflow.com/questions/1344908/how-do-i-stage-all-files-at-once-in-git-gui

  1. Click 'Tools'>Add...
  2. Name it whatever you want (I chose 'add all')
  3. In the 'Command' field, type git add *
  4. Optionally check the boxes to remove a dialog window, output window, and global configuration.
  5. Click the Add button in the bottom right.