add note about custom path do "As a Service" section

README.md

@@ -37,7 +37,8 @@
 
 # UI
 
-fan2go is a simple terminal client and controller daemon. To allow external programs to interact with it there is an API that
+fan2go is a simple terminal client and controller daemon. To allow external programs to interact with it there is an API
+that
 can be (optionally) enabled.
 
 ## UI Clients
@@ -484,6 +485,9 @@ sudo systemctl enable --now fan2go
 journalctl -u fan2go -f
 ```
 
+> NOTE: If you want to use a config path that differs from the default one, make sure to edit the
+> unit file and point the `-c` flag to the correct path.
+
 ## CLI Commands
 
 Although fan2go is a fan controller daemon at heart, it also provides some handy cli commands to interact with the