suggestion add Briar in **im_comparison.htm**

[Max-dc]

Hi,

I wanted to make a pull request with an adapted version of im_comparison.htm that included Briar. But I'm too slow to make it :/

Like there is not discussion tab on this repository , I write my suggestion here in the "issue" ...

So I would recommand to add Briar ! That seem the strongest privacy IM, but lack of few features (voice message .. )