message: docs(README): execution -> executable
  See:
diff: @@ -41,7 +41,7 @@ installers for all supported operating systems.
  #### AppImage
  -Set execution permissions on the `.AppImage` file and double-click it.
  +Set executable permissions on the `.AppImage` file and double-click it.
  #### Debian and Ubuntu based Package Repository (GNU/Linux x86/x64)
  