Adds Grunt to style guides

#### What's the plan?
Add Grunt to style guides since Bower from other PR wasn't working.

#### What's this PR do?
Adds in Grunt, festival Sass, TribTalk Sass, and Gemfile. Not sure why the commit from 7/29 is being included in this PR, but that h2 should be part of site footer typography section for TribTalk, so just leaving it.

#### How should this be manually tested?
* Run `npm install && bundle install`
* Then run `grunt`, `grunt dev`, `grunt build`, and `grunt sass` to check that tasks are running as desired.