docs: move cli into dedicated file

docs/README.md

@@ -39,7 +39,7 @@ npm install -g @vue/cli
 vue create my-project
 ```
 
-For full details on what the `vue` command can do, see the [full CLI docs](https://github.com/vuejs/vue-cli/blob/dev/packages/%40vue/cli/README.md).
+For full details on what the `vue` command can do, see the [full CLI docs](./cli.md).
 
 ## CLI Service
 

docs/cli.md

@@ -0,0 +1,58 @@
+## CLI Usage
+
+### Creating a New Project
+
+``` sh
+vue create my-project
+```
+
+<p align="center">
+  <img width="682px" src="https://raw.githubusercontent.com/vuejs/vue-cli/dev/docs/screenshot.png">
+</p>
+
+### Zero-config Prototyping
+
+You can rapidly prototype with just a single `*.vue` file with the `vue serve` and `vue build` commands, but they require an additional global addon to be installed:
+
+``` sh
+yarn global add @vue/cli-service-global
+echo '<template><h1>Hello!</h1></template>' > App.vue
+vue serve
+```
+
+`vue serve` uses the same default setup (webpack, babel, postcss & eslint) as projects created by `vue create`. It automatically infers the entry file in the current directory - the entry can be one of `main.js`, `index.js`, `App.vue` or `app.vue`. If needed, you can also provide an `index.html`, install and use local dependencies, or even configure babel, postcss & eslint with corresponding config files.
+
+The drawback of `vue serve` is that it relies on globally installed dependencies which may be inconsistent on different machines. Therefore this is only recommended for rapid prototyping.
+
+### Installing Plugins in an Existing Project
+
+Each CLI plugin ships with a generator (which creates files) and a runtime plugin (which tweaks the core webpack config and injects commands). When you use `vue create` to create a new project, some plugins will be pre-installed for you based on your feature selection. In case you want to install a plugin into an already created project, simply install it first:
+
+``` sh
+yarn add @vue/cli-plugin-eslint
+```
+
+Then you can invoke the plugin's generator so it generates files into your project:
+
+``` sh
+# the @vue/cli-plugin- prefix can be omitted
+vue invoke eslint
+```
+
+In addition, you can pass options to the plugin:
+
+``` sh
+vue invoke eslint --config airbnb --lintOn save
+```
+
+It is recommended to commit your project's current state before running `vue invoke`, so that after file generation you can review the changes and revert if needed.
+
+### Pulling `vue-cli@2.x` Templates (Legacy)
+
+`@vue/cli` uses the same `vue` binary, so it overwrites `vue-cli@2.x`. If you still need the legacy `vue init` functionality, you can install a global bridge:
+
+``` sh
+yarn global add @vue/cli-init
+# vue init now works exactly the same as vue-cli@2.x
+vue init webpack my-project
+```