docs: update README

README.md

@@ -1,8 +1,20 @@
 [![Retroarch Snap](https://snapcraft.io/retroarch/badge.svg)](https://snapcraft.io/retroarch)
+
 # RetroArch Snap
+
 This project creates a working snap of RetroArch.
 
 ## Current state
+
 This package will include assets, database, cheats,joypad autoconfig, info cores, overlay and shaders.
 
 You will need to use the Online Updater to install cores.
+
+## Daemon mode
+
+`snap.retroarch.service` will automatically enabled and started after installation on Ubuntu Core. On other versions of GNU/Linux to activate daemon run the following command:
+> WARNING! For most desktop distributions this is not needed
+
+```console
+$ snap set ubuntu-frame daemon=true && snap start --enable retroarch.daemon
+```