ISSUE 9: add download file functionality

src/components/DockBuilder/DockBuilder.jsx

@@ -103,11 +103,17 @@ export const DockBuilder = () => {
   // }, [ editor ] );
 
   const toJSON = () => {
-    // TODO: download the json file
-    // TODO: get json of editor content
-    // TODO: Ensure dockData is included in the json
-    // TODO: save the json to the local storage as dock
-    // TODO: name the file as paradise_dock_<timestamp here>.dock
+    // Get JSON of editor content, including dockData and snapClone
+    const json = editorMemo.toJSON(["dockData", "snapClone"]);
+    const data = JSON.stringify(json, null, 2);
+    // Save to localStorage
+    localStorage.setItem("dock", data);
+    const blob = new Blob([data], { type: "application/json" });
+    const anchor = document.createElement("a");
+    const timestamp = Date.now();
+    anchor.href = URL.createObjectURL(blob);
+    anchor.download = `paradise_dock_${timestamp}.dock`; // TODO: name the file as paradise_dock_<timestamp here>.dock
+    anchor.click();
   };
 
   const uploadFile = (e) => {