(PDB-608) Prepare PuppetDB indexes for 2.0.0-rc1

This creates the new index for PuppetDB 2.0.0, it also fixes some
obvious typos with both this index and the master one and configures the
git download process to obtain the docs soure for 2.0.0 from the pdb
stable branch.

Signed-off-by: Ken Barber <ken@bob.sh>