Create "sentence" transformation

[pokey]

It would be considered a delimited sequence, so that it would remove trailing periods as necessary. We probably want to use an NLP library for this one to do it properly

• [ ] In addition, it should understand that the first word should be capitalized, and other words don't need to, but may be. This capitalization support might share impl with camel-case (#34), eg how camel case should know that first is lower but rest are upper

sentence-splitter might be worth investigating