Added Swiftype meta tag to be used for search option titles instead of page titles.

Currently, both search results and search autocomplete display options are like this (searching for "Data"):

"Ember.js - Ember Data"
"Ember.js - Stabilizing Ember Data"
…

Adding Swiftype meta tags to be used instead of page title will change the results to this:

"Ember Data"
"Stabilizing Ember Data"
…

More about "st:title" meta tag here (https://swiftype.com/documentation/meta_tags)