Update import package name to V2 (#1693)

Author: gknapp

plugins/store/README.md

@@ -60,7 +60,7 @@ fn main() {
 Afterwards all the plugin's APIs are available through the JavaScript guest bindings:
 
 ```typescript
-import { Store } from "tauri-plugin-store-api";
+import { Store } from "@tauri-apps/plugin-store";
 
 const store = new Store(".settings.dat");