Remove reference to hljs in JavaScript, which cause error at http://developer.everydayhero.com

highlight.js library is removed at 12c5591edd513f14ffcb3f563bfa5435b2c844f5
It seemed some JavaScript files still refered on hljs variable which was provided by highlight.js. This PR removes these references, though I didn't test this because I couldn't run this app locally.