Add comments to webpack configs

addons/xterm-addon-ligatures/webpack.config.js

@@ -36,6 +36,7 @@ module.exports = {
     'util': 'util'
   },
   resolve: {
+    // The ligature modules contains fallbacks for node environments, we never want to browserify them
     fallback: {
       stream: false,
       util: false,

demo/start.js

@@ -51,6 +51,7 @@ const clientConfig = {
       browser: path.resolve('./out/browser')
     },
     fallback: {
+      // The ligature modules contains fallbacks for node environments, we never want to browserify them
       stream: false,
       util: false,
       os: false,