DOC: Pipeline docstring edits
DOC: Pipeline docstring edits

quantopian/zipline,bartosh/zipline,alphaBenj/zipline,magne-max/zipline-ja,humdings/zipline,bartosh/zipline,Scapogo/zipline,alphaBenj/zipline,humdings/zipline,florentchandelier/zipline,florentchandelier/zipline,magne-max/zipline-ja,quantopian/zipline,enigmampc/catalyst,Scapogo/zipline,enigmampc/catalyst