Updated: readme.md - Differentiate between `bundles` and `widgets`

I wasted about an hour looking for some caching mechanism or suchlike
because changes to views in `widgets/` were not appearing
live. Finally I noticed a commit message about transitioning to
`bundles/`. This should be in the ReadMe.
Merge pull request #24 from myqlarson/develop

Updated: readme.md - Differentiate between `bundles` and `widgets`