Document which browsers we support

[Daniel-Mietchen]

as per this comment from #390:

I think we should either decide on whether we want to use resources to support IE at the this time. And also document which browsers we want to test/support. (I'll also run into this with the code I am writing).

My suggestion is at least to test in Safari, Firefox and a Chromium-based browser. And to test on tablet and mobile as well as on desktop. As a part of #785, I'll document which browsers we target/support.

@fnielsen what do you think?

(Google Chrome, Microsoft Edge, Samsung Internet, Opera, Brave, etc. are all using the Chromium rendering engine. I do not know if we need to support IE – it has gone below 1% browser market share worldwide and requires much more work than the others, – as it does not implement recent standards).

[egonw]

It's a moving target. Is this something we can automate, the compatibility testing?

[larsgw]

This is also relevant for Citation.js, as I need to change the bundle depending on the targeted browser support.