fix(github docs): Includes @angular/cdk in installation instructions (#5555)

* includes @angular/cdk in github material installation instructions

* Mention the latest builds instructions

Add the latest builds instructions in the installation section (Step 1).

* Delete the installation section

The Getting Started section has all the information necessary to proceed with installations: #5552 (comment)

Author: julianobrasil

README.md

@@ -11,18 +11,6 @@ This is the home for the Angular team's Material Design components built for and
 [Contributing](https://github.com/angular/material2/blob/master/CONTRIBUTING.md) |
 [Plunker Template](http://plnkr.co/edit/o077B6uEiiIgkC0S06dd?p=preview)
 
-### Installation
-
-The latest release of Angular Material can be installed from npm
-
-`npm install @angular/material`
-
-A snapshot build with the latest changes from
-[master](https://github.com/angular/material2/tree/master) is also available.
-Note that this snapshot build should not be considered stable and may break between releases.
-
-`npm install --save angular/material2-builds angular/cdk-builds`
-
 ### Getting started
 
 See our [Getting Started Guide][getting-started]

guides/getting-started.md

@@ -9,6 +9,12 @@ For existing apps, follow these steps to begin using Angular Material.
 npm install --save @angular/material @angular/cdk
 ```
 
+A snapshot build with the latest changes from master is also available. Note that this snapshot build should not be considered stable and may break between releases.
+
+```bash
+npm install --save angular/material2-builds angular/cdk-builds
+```
+
 ## Step 2: Animations
 
 Some Material components depend on the Angular animations module in order to be able to do