Add “flexbugs” link to Flexbox info

[ihorzenich]

Many pages contain tips about browser support of each feature, “Flexbox“ page include them too, but it seems like it missing perfect FAQ about flexbox bugs and its workarounds.

I think it would be good to add it, I can create pull request for it.

[mischah]

Hej, good idea.

A pull request is welcome. You could also replace one of these: »Flexbox Please!, Flexy Boxes, and Flexplorer.« with http://codepen.io/osublake/pen/dMLQJr