Fix: refreshing the page while selecting saves the selection ele… (#601)

* Fix: refreshing the page while selecting saves the selection element

Fixes #591.

* fix lint

Co-authored-by: David Luzar <luzar.david@gmail.com>

src/index.tsx

   }
 
   private saveDebounced = debounce(() => {
-    saveToLocalStorage(elements, this.state);
+    saveToLocalStorage(
+      elements.filter(x => x.type !== "selection"),
+      this.state,
+    );
   }, 300);
 
   componentDidUpdate() {