v0.3.0

• Added keyboard navigation setting (requires a mouseover on a Slidr to trigger)
• Added touch (swipe) navigation for mobile
• Performance improvements:
  • Refactored keyframe creation - now generates a set of static, reusable animations instead of creating globally unique animations per Slidr
  • Use a single global timer to poll for resize, instead of individual timers per Slidr
  • Added a subtle transition effect when a Slidr resizes
  • Remove tap highlights and user-select on mobile
  • Correctly allow recreating a Slidr if it gets removed from the DOM and reinserted