Update README.md

Author: Brian Muenzenmeyer

README.md

@@ -1,3 +1,5 @@
 ## The Mustache engine for Pattern Lab / Node
 
 This one should be included by default with Mustache editions. If it's missing from your project for any reason, `npm install patternengine-node-mustache` should do the trick.
+
+On dev right now the command is `npm install pattern-lab/patternengine-node-mustache#dev`