User can download a performance into a word document

Worlds most unnecessarily long PR
*User can add a description to word document
*User can use markdown in description
*User can download performance into word document
*User can see formatted list of contacts on performance page
*If no contact is listed, user sees "No contact listed"

@ChristopherThorsen, @GarthGoldwater - please have a look
This can just be: `change_column_null :performances, :description, false`