Basic Javascript Github Issues Aggregator + small fixes

This is based off of #19 though it uses Javascript instead to fetch the data client-side without the need of a cron job to update the data. 

-Currently doesn't work on the initial load likely due to a scope issue, but works fine after selecting a non-default dropdown item.
-Added read-only API token to config.json

-Fixed some logic on what issues to display in main.js.
-Added missing </img> tag in issues template.