Add github access token

Author: kyb3r

app.json

@@ -22,6 +22,10 @@
     "LOG_URL": {
         "description": "The url of the logviewer app for viewing selfhosted logs",
         "required": true
+    },
+    "GITHUB_ACCESS_TOKEN": {
+        "description": "Your personal access token for GitHub, adding this gives you the ability to use the 'update' command, which will sync your fork with the main repo.",
+        "required": false
     }
   }
 }