[Gimp-web] Which social media sites shall we support?

Let's move this topic to a separate topic.

For the Share buttons at the bottom of blog posts, it's pretty easy to
just add another link, and I think the limiting factor should be more
about design -- a million little icons will make the page look
cluttered. A solution to this which I like is to have a single Share
button, which toggles the display of all the different social media
icons.

However, getting users to *subscribe* to our social media profiles
means giving them content to follow -- and each extra social site makes
reposting GIMP-related links more tedious. So we'll want to be
strategic about which platforms we use:

* We've talked before about Twitter and Google+.
* Facebook is too big to ignore, I think.
* Ello has the nicest visual design of any social media site I've seen,
so I personally like it a lot. It's still fairly small and new, though.
* Tumblr, Deviant Art, Instagram and maybe Pinterest have large
communities of artists, so there are likely many GIMP users there.

Flickr is maybe *too* focused on uploading original images to work for
this sort of thing? But there is a somewhat active GIMP Users group
already.

~Andrew T