Adds attract mode uses Reveal's autoSlide feature. Timer reset on button press. Slide delay is determined by autoslide-<number> classname, which is added as data-autoslide attribute when attract mode engages.
Fixes bug that caused autoSlide to skip slides. Using linear transition so background will be easier
Uses more realistic timing for attract mode (30s to start, 5s between slides)
Merge pull request #11 from justinjams/addAttractMode

Add attract mode
Working on different keys and execution