add manifest json

Author: kevinluo201

app/views/layouts/application.html.erb

@@ -5,6 +5,7 @@
     <meta name="viewport" content="width=device-width,initial-scale=1">
     <%= csrf_meta_tags %>
     <%= csp_meta_tag %>
+    <link rel="manifest" href="/manifest.json">
 
     <%= stylesheet_link_tag "application", "data-turbo-track": "reload" %>
     <%= javascript_importmap_tags %>

public/manifest.json

@@ -0,0 +1,4 @@
+{
+  "name": "Calmmigration",
+  "display": "standalone"
+}