Remove .env

Replace %REACT_APP_ENV% with <noscript> to avoid
having to add REACT_APP_ENV placeholder to .env file
during development.

Author: zmeyc

Diff for: .env

@@ -9,6 +9,6 @@ ENV_JSON="$(jq --compact-output --null-input 'env | with_entries(select(.key | s
 # Inside of JSON strings newlines are already escaped.
 ENV_JSON_ESCAPED="$(printf "%s" "${ENV_JSON}" | sed -e 's/[\&/]/\\&/g')"
 
-sed -i "s/%REACT_APP_ENV%/${ENV_JSON_ESCAPED}/g" /var/www/index.html
+sed -i "s/<noscript id=\"env-insertion-point\"><\/noscript>/<script>var ENV=${ENV_JSON_ESCAPED}<\/script>/g" /var/www/index.html
 
 exec "$@"

Diff for: docker-entrypoint.sh

@@ -23,9 +23,7 @@
       Learn how to configure a non-root public URL by running `npm run build`.
     -->
 
-    <script>
-      var ENV = %REACT_APP_ENV%;
-    </script>
+    <noscript id="env-insertion-point"></noscript>
 
     <title>React App</title>
   </head>