file module doc update, and pkg state update for names.

This is a change to the file module to add the supported hash types via a note and resolves https://github.com/saltstack/salt/issues/10363. This PR also adds the 'names' option to pkg.installed, and some basic docs that are pretty much a copy and paste of the 'pkgs' docs, as I believe they support the same options (if this is incorrect feel free to let me know). Resolves https://github.com/saltstack/salt/issues/10003.