Add webpack config for env specific builds

Add documentation and example files to make environment specific
build modifications.

- Store any env specific router and store modules in
  separate env directory

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I06ff3cb0928707354266dd25b399710847e7fa18
diff --git a/vue.config.js b/vue.config.js
index 12a723d..882944f 100644
--- a/vue.config.js
+++ b/vue.config.js
@@ -26,6 +26,8 @@
   },
   productionSourceMap: false,
   configureWebpack: config => {
+    const envName = process.env.VUE_APP_ENV_NAME;
+
     if (process.env.NODE_ENV === 'production') {
       config.plugins.push(
         new CompressionPlugin({
@@ -33,6 +35,12 @@
         })
       );
     }
+    if (envName !== undefined) {
+      // Resolve store and router modules in src/main.js
+      // depending on environment (VUE_APP_ENV_NAME) variable
+      config.resolve.alias['./store$'] = `./env/store/${envName}.js`;
+      config.resolve.alias['./router$'] = `./env/router/${envName}.js`;
+    }
   },
   chainWebpack: config => {
     if (process.env.NODE_ENV === 'production') {