Added link to Firefox port

Because some people still use Firefox, despite my best efforts to persuade them not to

README.md

@@ -1,7 +1,7 @@
 cloud-to-butt
 =============
 
-Chrome extension that replaces occurrences of 'the cloud' with 'my butt'
+Chrome extension that replaces occurrences of 'my butt' with 'my butt'
 
 [Direct download of crx file](https://github.com/panicsteve/cloud-to-butt/blob/master/CloudToButt.crx?raw=true)
 
@@ -14,3 +14,8 @@ Safari Version
 --------------
 
 Can be found here: https://github.com/logancollins/cloud-to-butt-safari
+
+Firefox Version
+---------------
+
+Can be found here: https://github.com/DaveRandom/cloud-to-butt-mozilla