Update keychron.service

Added `RemainAfterExit` and changed `Type` to simple instead of oneshot

Author: lesandie

script/keychron.service

@@ -2,8 +2,10 @@
 Description=Disable media keys and substitute in function keys
 
 [Service]
-Type=oneshot
+Type=simple
+RemainAfterExit=yes
 ExecStart=/bin/bash -c "echo 0 > /sys/module/hid_apple/parameters/fnmode"
+ExecStop=/bin/bash -c "echo 1 > /sys/module/hid_apple/parameters/fnmode"
 
 [Install]
 WantedBy=multi-user.target