Docs should indicated that tandem assets need to be added

[mcwqy9]

Just need to update the docs to say to include

  config.assets.precompile += %w( 
                                      tandem.css 
                                      tandem.js 
                                      tandem/wymeditor/*.js
                                      tandem/wymeditor/*/*.js
                                      tandem/wymeditor/*/*.css )

in production.rb and why.