Add slides URL

Dependencies

• [2] GHBCQL5F Speaker notes improvements
• [3] QUG3TDX3 Update to reveal.js 4.1 and a few small fixes
• [4] W7EIQGVR Progress
• [*] UH3YXOLF Start the slide deck

Change contents

• replacement in index.html at line 111
  [2.487]→[2.487:550](∅→∅)
  − <strong>Time Elapsed: 45 min.</strong>
  [2.487]

  [2.550]
  + <strong>Time Elapsed: 59 min.</strong>
• replacement in index.html at line 137
  [3.5322]→[2.1135:1260](∅→∅)
  − href="https://bit.do/utrechtjug-successor-of-git">bit.do/utrechtjug-successor-of-git</a>
  [3.5322]

  [3.5503]
  + href="https://bit.do/utrechtjug-successor-git">bit.do/utrechtjug-successor-git</a>