Provide a way to create a grid around theme words

[philhanna]

Requirements

Currently, the system has you create a grid and then create a puzzle from it. The grid has to be complete before you start working on the puzzle. But a better workflow for themed puzzles is to

1. Come up with the theme words (usually 4 words, which will be the longest in the puzzle)
2. Experiment with how to place them on a grid
   • Must be in symmetrical places on the grid
   • Probably need for pairs to cross each other
3. After the right placement is found:
   • Create the grid
   • Create a puzzle from that
   • Add the theme words at the location decided upon \ See How to make a crossword puzzle grid in the New York Times.

[philhanna]

See issue #113