feat(*): renamed directives to be more logical
feat(*): renamed directives to be more logical

BREAKING CHANGE: `ctn-curtain` is now `ctn-curtains` and `ctn-section`
is now `ctn-curtain`.

joshdmiller/ng-curtain,programbo/ng-curtain,pbawebsite/ng-curtain,pbawebsite/ng-curtain,programbo/ng-curtain