Create Page Block for exhibit

[eam5]

Continue work on creating page block for Neatline exhibit. See 59a1cde6b60790c6f8ad01d4e1a5025c32785017

Page block should insert exhibit map on a page -include settings for including exhibit title, and exhibit narrative

[jamiefolsom]

@dleadbetter moving this back into v1.0.0. Once the other items in that milestone are complete, let's take this one on.

[dleadbetter]

Pull request is in the performant-software/neatline-3 repo.

• From the admin view, navigate to Sites and select a Site to edit
• Navigate to Pages, select a page to edit
• From the page edit, use the right menu to select a "Neatline Exhibit" block
• Select an exhibit to add
• Save the record, click "View" to view the page with the new block added