Revert "More documentation on design"

This reverts commit c95f1b60089953924859654d025589e830731026.
Revert "changed to relative imports; no more PYTHONPATH, I hope"

This reverts commit 0d0f91792990fdd97edcec56de5e9bddf91308a2.
Merge branch 'master' of https://github.com/bmuk/pyrogue