delete redundant files for better project view

Author: KeenWarrior

public/index.html

@@ -8,7 +8,7 @@
       content="width=device-width, initial-scale=1, shrink-to-fit=no"
     />
     <meta name="theme-color" content="#000000" />
-    <link rel="manifest" href="%PUBLIC_URL%/manifest.json" />
+    <link rel="manifest" crossorigin="use-credentials" href="%PUBLIC_URL%/manifest.json" />
     <link
       href="https://fonts.googleapis.com/css?family=Roboto+Mono|Roboto+Slab|Roboto:300,400,500,700"
       rel="stylesheet"