Add longer, plain language version of "Purpose and Objectives" page

[bletalien]

I don't know how we want to link to it. Maybe just make "Purpose and Objectives" on the homepage a link?

What URL do we want to give it? /BaselineTestPages/PurposeObjectives?

Do we have rules on constructing URLs?

I'll go figure out how to create the new page and put in a pull request for it. I have the draft language thanks to Kathy and Ann Marie.

[bletalien]

See #37