Add usage

Author: nomcopter

README.md

@@ -6,6 +6,32 @@ An opinionated Yeoman Generator for a Typescript + React ready build system.
 
 ## Usage
 
+1. Install [Yo](http://yeoman.io/)
+
+    ```bash
+    # yarn
+    yarn global add yo
+
+    # npm
+    npm install -g yo
+    ```
+1. Install the generator globally
+
+    ```bash
+    # yarn
+    yarn global add generator-typescript-react
+
+    # npm
+    npm install -g generator-typescript-react
+    ```
+1. Create the directory for your new project and run the generator
+
+    ```bash
+    mkdir new-typescript-react-project
+    cd !$
+    yo typescript-react
+    ```
+
 ## Upgrade Considerations / Changelog
 
 See [Releases](https://github.com/palantir/react-mosaic/releases)