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
If two users download a file at the same time, the second one's `tmp/performance.docx` will overwrite the first one's `tmp/performance.docx` and they will both download the second person's file. How about passing in an `id` to this class's initialize and doing this:

```ruby
zipfile_name = Rails.root.join("tmp/performance-#{id}.docx")
```

so that each user is generating a different file?