Add Stack Exchange

[u1735067]

Ref. file from https://stackoverflow.com/company/logos
Background color from the https://stackexchange.com/ title bar (.top-bar)
Minified using https://jakearchibald.github.io/svgomg/

[edent]

This is really good! Please can you make a few changes.

1. Remove the class="...." stuff. It isn't needed.
2. You can make it smaller by rounding up the decimal places.
3. Please follow https://github.com/edent/SuperTinyIcons/blob/master/CONTRIBUTING.md - and then I'll merge it.

Thank you once again :-)

[u1735067]

Class removed, added to ref & radius.
I don't have/know the tools to round the decimals automatically. As this is not the final size, I did not add it to readme.md.