Adding OpenSUSE instructions, and fix leftover garbage text at bottom of prepare.md
Add open-suse instructions, noting that Tumbleweed is not yet known to work. Will send a second MR when I get tumbleweed to work, and when Leap 42.2 is out, if any further changes arise.
Bottom of the file should have probably just linked to the real installation instructions. I tried to fix that too.
Visual review: https://gitlab.com/warren.postma/gitlab-development-kit/blob/readme-add-opensuse/doc/prepare.md
OpenSuSE Tumbleweed 20161109 is blocked on problems with libicu support from the charlock_holmes gem at this time.