Improve the Accounts Template notes in YAML files.

- Improve the wording and grammar of template notes.
- Fix formatting and/or wording for a few of the default
  templates.
Fix typo on landing.yaml
Merge pull request #745 from beckonandmuse/issue/template-notes

Improve the Accounts Template notes in YAML files.

Reviewed-By: Jared Hancock <jared@osticket.com>