Major update: Add Environment variables support

README.md

@@ -73,3 +73,14 @@ The config file is a json file that contains all the information needed to run t
     }
 ]
 ```
+
+You can also use environment variables in the config file. Example:
+
+```json
+[
+    {
+        "title": "Sync Folders",
+        "folders": ["$FOLDER_1", "$FOLDER_2"]
+    }
+]
+```