add Docs for Filter

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)
Merge branch 'BHV-8192' of github.com:enyojs/enyo into BHV-8192
docs for BucketFilter

Enyo-DCO-1.1-Signed-Off-By: Cole Davis (cole.davis@lge.com)