html-webpack-loader makes server/build use same src/index.html file

Added option for dev proxy by passing env variable: proxyhost.
File definitions and paths defined by variables instead of rewriting
string

package.json

@@ -29,6 +29,7 @@
     "css-loader": "6.7.0",
     "documentation": "^11.0.0",
     "file-loader": "6.2.0",
+    "html-webpack-plugin": "^5.5.0",
     "sass": "1.49.9",
     "sass-loader": "12.6.0",
     "terser-webpack-plugin": "5.3.1",