Update doc to use cm-12.0 instead of 11.0 for cm-12.0 branch

Change-Id: Icfc92fb373506be24b6d73c2235dacca49acc640
Update manifest for cm-12.0

Change-Id: Ic9285dc8b2d04549636da5b57b0f003b5d850302
Merge remote-tracking branch 'cyanogen/cm-12.0' into cm-12.0