docs: Add FAQ on version 4.6.2 error message (#265)

Describes the solution to fix the error mesage when bundling with version 4.6.2

Author: rojakcoder

docs/faqs.md

@@ -7,4 +7,21 @@
   `vue-template-compiler` has a constraint that it should be exact same version as `vue` that is why it is included as peer dependency. Make sure you install `vue-template-compiler` and `vue` in your project.
 
 - **Error: Cannot find module `less` or `node-sass` or `stylus`?**  
-  If you're using any of the style languages (other than css) supported in `.vue` file, you have to install that language's compiler.
+  If you're using any of the style languages (other than css) supported in `.vue` file, you have to install that language's compiler.
+  
+- **Error: 'default' is not exported by node_modules/vue-runtime-helpers/dist/normalize-component.js**  
+  You may encounter this error when using version 4.6.2 onwards. The solution is to include `rollup-plugin-commonjs`. In your config file `rollup.config.js`, you have to import this plugin and invoke it like so:
+  
+  ```
+  import vue from 'rollup-plugin-vue';
+  import commonjs from 'rollup-plugin-commonjs';
+
+  export default {
+    entry: 'index.js',
+    plugins: [
+      commonjs(),
+      vue(),
+    ]
+  }
+  ```
+