improve intro for absolute beginners (close vuejs#565)

Author: yyx990803

src/guide/index.md

@@ -12,7 +12,15 @@ If you are an experienced frontend developer and want to know how Vue compares t
 
 ## Getting Started
 
-The easiest way to try out Vue.js is using the [JSFiddle Hello World example](https://jsfiddle.net/chrisvfritz/50wL7mdz/). Feel free to open it in another tab and follow along as we go through some basic examples. If you prefer downloading / installing from a package manager, check out the [Installation](/guide/installation.html) page.
+<p class="tip">The official guide assumes intermediate level front-end knowledge of HTML, CSS and JavaScript. If you are totally new to front-end development, it might not be the best idea to jump right into a framework as your first step - grasp the basics then come back! Prior experience with other frameworks helps, but is not required.</p>
+
+The easiest way to try out Vue.js is using the [JSFiddle Hello World example](https://jsfiddle.net/chrisvfritz/50wL7mdz/). Feel free to open it in another tab and follow along as we go through some basic examples. Or, you can simply create an `.html` file and include Vue with:
+
+``` html
+<script src="https://unpkg.com/vue/dist/vue.js">
+```
+
+The [Installation](/guide/installation.html) page provides more options of installing Vue. Note that we **do not** recommend beginners to start with `vue-cli`, especially if you are not yet familiar with Node.js-based build tools.
 
 ## Declarative Rendering
 

src/guide/installation.md

@@ -46,7 +46,9 @@ $ npm install vue
 
 ### Standalone vs. Runtime-only Build
 
-There are two builds available, the standalone build and the runtime-only build.
+There are two builds available, the standalone build and the runtime-only build. The difference being that the former includes the **template compiler** and the latter does not.
+
+The template compiler is responsible for compiling Vue template strings into pure JavaScript render functions. If you want to use the `template` option, then you need the compiler.
 
 - The standalone build includes the compiler and supports the `template` option. **It also relies on the presence of browser APIs so you cannot use it for server-side rendering.**
 
@@ -87,6 +89,8 @@ $ npm install
 $ npm run dev
 ```
 
+<p class="tip">The CLI assumes prior knowledge of Node.js and the associated build tools. If you are new to Vue or front-end build tools, we strongly suggest going through the <a href="/guide">guide</a> without any build tools before using the CLI.</p>
+
 ## Dev Build
 
 **Important**: the built files in GitHub's `/dist` folder are only checked-in during releases. To use Vue from the latest source code on GitHub, you will have to build it yourself!