- cra-project/public/index.html
<% for ( var css in htmlWebpackPlugin.files.css ) { %>
<link rel="preload" as="style" href="<%=htmlWebpackPlugin.files.css[css]%>" as="style" onload='this.rel="stylesheet"'>
<% } %>
<% for ( var js in htmlWebpackPlugin.files.js ) { %>
<link rel="preload" as="script" href="<%=htmlWebpackPlugin.files.js[js] %>" as="script">
<% } %>