Add namespaced packs feature to readme (#235)
Add namespaced packs feature to readme (#235)

* Add namespaced packs feature to readme

* Clarify usage of namespaced packs

gauravtiwari/webpacker,Davidzhu001/webpacker,gauravtiwari/webpacker,usertesting/webpacker,rossta/webpacker,Davidzhu001/webpacker,rossta/webpacker,usertesting/webpacker,Davidzhu001/webpacker,rails/webpacker,rails/webpacker,usertesting/webpacker,rossta/webpacker,rossta/webpacker,gauravtiwari/webpacker