Clear up development instructions

`npm link` is not necessary for local development as we can just call
the cli from the build directory.

README.md

@@ -21,16 +21,12 @@ vip login
 
 ## Development
 
-To start hacking the vip-cli, follow the instructions below.
+To start hacking:
 
-1. clone this repository: `git clone https://github.com/Automattic/vip-cli`
-1. cd to the clonned directory `cd vip-cli`
-1. run `npm link`
+1. clone the repository: `git clone https://github.com/Automattic/vip-cli`
+1. cd to the cloned directory `cd vip-cli`
+1. run `npm install` to install dependencies
 1. hack the code
-1. run `npm install`
-1. use the `vip` command with your modified code
+1. test your changes by calling `node build/bin/vip.js`
 
-### Automattic developers:
-
-Please note, that running the `npm install` will override your local installation on your sandbox and you'll have to `vip login` again.
-Once you are done hacking, you'll have to run `npm install -g wpvip-cli@latest` again in order to restore the current production installation on your sandbox.
+Note: Your development version will use the same config as the globally installed module and any changes to the config will impact that.