- [x] move fully from github to cgit
  - [x] copy the github issues to this file
  - [x] update stackoverflow links to cgit
  - [x] update app links to cgit
  - [x] add note about sending patches and remarks via email in readme

- [x] use a button to open popups (to avoid triggering popup blockers)
  - [x] confirm whether action clicks do not trigger the blocker
  - [x] remove redundant popup blocker check at start

- [x] add a donation link to the app

- [x] support `\setbeameroption{show notes on second screen=bottom}`
      (more convenient for prints and previews)
      (can be auto-detected with the greatest size dimension)
      (need to update the documentation on the homepage)

- [ ] Add the current local time
      (next to the timer?)

- [ ] Add a loading indicator
      (Showing that PDFJs is still loading and that the app is not ready yet).
      (Could replace the "available offline too" mention, which is a bit
      confusing anyway).

- [ ] Fix wrong size of first slide in Chrome (minor bug):
      The first slide is sometimes loaded with the wrong size.
      This goes away on windows resize or slide change.
      But it would be nice for this not to be happening in the first place.
      That's most likely due to some race-condition on window creation.

- [ ] Selectable text layer:
      Add a selectable text layer on top of the rendered canvas,
      allowing the user to copy text and click on embedded links.

- [ ] Slider overview:
      Display a thumbnails grid of all the slides to the presenter,
      making jumping between slides faster.

- [ ] Display audience slide on speaker screen:
      Display the slide shown to the audience full-screen on the speaker's
      screen when maintaining a button pressed for example.

- [ ] Highlight, pointer and spotlight:
      Add something similar to what Impressive does,
      allowing the presenter to highlight parts of the slide during the
      presentation.
      (https://impressive.sourceforge.net/)