Add build-time environment variable for enabling windchimes

Disabled by default for development where those requests
get blocked by CORS and are just noise.

Author: GarboMuffin

src/containers/tw-windchime-submitter.jsx

@@ -8,6 +8,10 @@ const OPT_OUT_KEY = 'tw:windchime_opt_out';
 const submittedThisSession = new Set();
 
 const isOptedOut = () => {
+    if (!process.env.ENABLE_WINDCHIMES) {
+        return true;
+    }
+
     try {
         const local = localStorage.getItem(OPT_OUT_KEY);
         if (local !== null) {

webpack.config.js

@@ -179,7 +179,8 @@ module.exports = [
                 'process.env.DEBUG': Boolean(process.env.DEBUG),
                 'process.env.ENABLE_SERVICE_WORKER': JSON.stringify(process.env.ENABLE_SERVICE_WORKER || ''),
                 'process.env.ROOT': JSON.stringify(root),
-                'process.env.ROUTING_STYLE': JSON.stringify(process.env.ROUTING_STYLE || 'filehash')
+                'process.env.ROUTING_STYLE': JSON.stringify(process.env.ROUTING_STYLE || 'filehash'),
+                'process.env.ENABLE_WINDCHIMES': JSON.stringify(process.env.ENABLE_WINDCHIMES || '')
             }),
             new HtmlWebpackPlugin({
                 chunks: ['editor'],