(doc) Note more mask in type description
(doc) Note more mask in type description

Mask is the numeric representation of the bit flags.
This adds the note to further describe it.

cyberious/puppetlabs-acl,cyberious/puppetlabs-acl,MelanieGault/puppetlabs-acl,puppetlabs/puppetlabs-acl,ferventcoder/puppetlabs-acl,ferventcoder/puppetlabs-acl,MelanieGault/puppetlabs-acl,DSI-Ville-Noumea/puppetlabs-acl,DSI-Ville-Noumea/puppetlabs-acl,cowofevil/puppetlabs-acl,cowofevil/puppetlabs-acl