Update README.md (#1612)

#1517

Author: hovancik

README.md

@@ -463,6 +463,7 @@ You can help to translate Stretchly on [Weblate](https://hosted.weblate.org/enga
 
 
 ## Known issues
+- Autostart does not work in Flathub app ([#1517](https://github.com/hovancik/stretchly/issues/1517))
 - idle time detection doesn't work on Wayland ([electron/electron#27912](https://github.com/electron/electron/issues/27912))
 - Windows Store build's autorstart is not working, so was disabled. You need to do it [manually](https://www.lifewire.com/change-startup-programs-windows-11-6823499).