Added comment to explicit the usage of a custom config file

aindustries-be.service

@@ -9,6 +9,8 @@ RestartSec=1
 # Change with proper user to run the service
 User=web
 # Change with the installation location of the executable
+# It is possible to use a custom config file location
+# by adding '--config /path/to/config.toml' to the command bellow
 ExecStart=/usr/share/bin/aindustries-be
 
 [Install]