[enh] add appimage build command in README.md

README.md

@@ -142,5 +142,13 @@ Deploy the package on the PyPi repository (prefix the command with a space in or
 [SPACE]make deploy PYPI_LOGIN=xxxx PYPI_PASSWORD=xxxx
 ```
 
+### AppImage
+
+```bash
+make appimage
+```
+The make command will do a wheel build, then create the AppImage file `ci/appimage/Sakia_x86_64.AppImage`
+
+
 ## License
 This software is distributed under [GNU GPLv3](https://raw.github.com/duniter/sakia/dev/LICENSE).