Give install instructions

Author: kegsay

README.md

@@ -2,6 +2,17 @@
 
 This is a fork of [node-irc](http://node-irc.readthedocs.org/), which is an IRC client library written in [JavaScript](http://en.wikipedia.org/wiki/JavaScript) for [Node](http://nodejs.org/). This fork is used by the [Matrix-IRC application service](http://github.com/matrix-org/matrix-appservice-irc).
 
+To use this fork:
+```
+  npm install matrix-org/node-irc
+```
+
+Alternatively:
+```javascript
+"dependencies": {
+  "irc": "matrix-org/node-irc#commithash"
+}
+```
 
 You can access more detailed documentation for this module at [Read the Docs](http://readthedocs.org/docs/node-irc/en/latest/)