This removes the margin with the background gradient and such
completely once the screen falls under 700px. In those cases we really
don't want to waste space, and having just a weird blue bit above the
docs looks weirder than not having anything.
The sidebar had a fixed 230px, which is absolutely untenable if your
phone has 700px in total and we only use 85% of that.
So this moves the sidebar to the bottom for now, which isn't *great*,
but at least it leaves the text readable and allows navigating the ToC.
One of these days I'll understand what the heck CSS is.
[ci skip]
Released under the Python Software Foundation License, this one
doesn't look awful (no green top bar, huzzah!).
Lightly forked it to remove the donation footer (we don't take any)
and to change the python references to fish references.
The image is just our favicon, which is a stylized "f" and therefore
not fantastic (are we facebook?), but it's the best I found, and the
thing before had no images at all.
Fixes#6500
(as far as I'm concerned)
