README - correct link (MINOR)

Author: App Generator

README.md

@@ -311,4 +311,4 @@ Visit `http://localhost:8001` in your browser. The app should be up & running.
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-[Flask Black Dashboard](https://appseed.us/admin-dashboards/flask-dashboard-black) - Provided by **AppSeed [App Generator](https://appseed.us/app-generator)**.
+[Flask Dashboard](https://appseed.us/admin-dashboards/flask) Argon - Provided by **AppSeed [App Generator](https://appseed.us/app-generator)**.