doc: Format edits. Excised much of network discussion. Added reference to network guide.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Excised network settings.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added network settings. Reorganized index.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added a new network configuration reference document.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>