user-manual: replace init-db by init
user-manual: replace init-db by init

Replace mentions of init-db by mentions of init.

Signed-off-by: J. Bruce Fields <51738506c1b2ccb0761f23bdc612c93babf738ea@citi.umich.edu>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git