Preserve whitespace for strings on show page

Created by: gracewashere

Problem: Long description fields were being all mashed onto a single line on the 'show' page, making it difficult to read.

https://trello.com/c/xueiirQV

Solution: Add a CSS class to mark the type of each attribute on the show page, then add a rule to preserve whitespace.

Before:

After:

• update the CHANGELOG

Tags: #ruby, #design