[DOC] Clean up install markdown.
[DOC] Clean up install markdown.

xdv/gatewayd,zealord/gatewayd,zealord/gatewayd,crazyquark/gatewayd,whotooktwarden/gatewayd,xdv/gatewayd,whotooktwarden/gatewayd,Parkjeahwan/awegeeks,Parkjeahwan/awegeeks,crazyquark/gatewayd