Document upgraded contact messages

Content needed

We've upgraded the contact system to include new features. The work is currently in review, and it may make it into Janeway 1.9.

• Contact people used to be separate records in the DB, but now they are linked to user accounts, so rather than re-entering email, name, etc., users are shown a screen where they select a person to be a contact person, and then enter something for the contact's role, and save.
• You cannot change the account associated with a contact person record. So it's best to delete the old one and make a new one, if you need to change the account.
• Before, contact messages would just get sent via email. Now they are sent via email and viewable as logs within Janeway, under Manager --> Contact Messages. Users can view and delete messages. The help text on the page explains who can view what, and gives hints for messages that might not be showing. In some cases, old contact messages (ones from before this feature) could not be linked up to the journal or press, so they can only be accessed by people with admin or superuser access.
• If a contact person is deleted, the contact messages are still accessible by the account holder via the Contact Messages view.
• If an account is deleted, the associated Contact Person will be deleted as well, but not the messages.
• There is a new email template called Contact Message for the contact messages, so journals can customize the footer that gets sent along with the contact message. The default footer just says The above was sent from the <a href="">contact page for [journal or press name]</a> by [email].
• More details are in the dev docs: https://github.com/openlibhums/janeway/blob/22f9199749031606bbbd470bf0fdcda43a2bc309/docs/md/contact-messages.md

Related development

• https://github.com/openlibhums/janeway/pull/4845

Start with docs/md/contact-messages.md from the referenced Janeway development work. Compare the documentation with the listed contact-person, message visibility, deletion, and email-template behavior, then update the documentation to cover the missing details. Done means the documented behavior matches the upgraded contact system and its default footer.