Improve README.md

Author: Kocal

README.md

@@ -1,12 +1,39 @@
 # vue-web-extension-boilerplate
 
+This template allows you to quickly start a web extension containing:
+
+- Boilerplate for `manifest.json` and `background.js` files, and for `icons` / `popup` folders,
+- Vue,
+- Vue-router (configurable),
+- Vuex (configurable),
+- Webpack,
+- CSS extraction,
+- A Bash script for removing `eval` usages to comply with the Content Security Policy of Chrome/Firefox web store, is automatically called at each build,
+- A Python script to automatically bundle your extension into a zip file.
+
+## Requirements
+
+- Node.js >= 6 and npm >= 3,
+- [git](https://git-scm.com),
+- [vue-cli](https://github.com/vuejs/vue-cli)
+
 ## Usage
 
 ```bash
-$ npm install -g vue-cli
 $ vue init kocal/vue-web-extension my-extension
 $ cd my-extension
 $ npm install
 $ npm run build
 ```
 
+### `npm run build` 
+
+Build the extension into `dist` folder.
+
+### `npm run watch`
+
+Watch modifications then run `npm run build`
+
+### `python scripts/build-zip`
+
+Build a zip-file following this format « `<name>`-`<version>`.zip », by reading `name` and `version` from `manifest.json` file.