feat(v2): separate runtimechunk (#1355)

* feat(v2): separate runtimechunk

* nits

packages/docusaurus/lib/commands/start.js

@@ -86,8 +86,6 @@ module.exports = async function start(siteDir, cliOptions = {}) {
     plugins: [
       // Generates an `index.html` file with the <script> injected.
       new HtmlWebpackPlugin({
-        inject: false,
-        hash: true,
         template: path.resolve(
           __dirname,
           '../client/templates/index.html.template.ejs',

packages/docusaurus/lib/webpack/client.js

@@ -20,6 +20,11 @@ module.exports = function createClientConfig(props) {
     entry: {
       main: path.resolve(__dirname, '../client/clientEntry.js'),
     },
+    optimization: {
+      // Keep the runtime chunk separated to enable long term caching
+      // https://twitter.com/wSokra/status/969679223278505985
+      runtimeChunk: true,
+    },
     plugins: [
       // Generate manifests file
       new ReactLoadableSSRAddon({