Issue #974 Moves help website url to admin user pages

[Jake-Bodin]

Description

To allow non-admins to control OED as much as possible, moves help website url to be a part of the admin user pages. The default value is the standard location of OED help on the web (current value set by code).

Fixes #974

Type of change

• [x] Note merging this changes the database configuration.
• [x] This change requires a documentation update

Checklist

(Note what you have done by placing an "x" instead of the space in the [ ] so it becomes [x]. It is hoped you do all of them.)

• [x] I have followed the OED pull request ideas
• [x] I have removed text in ( ) from the issue request
• [x] You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

Limitations

Merge Conflicts - at least 6 Discussed with project lead who decided to handle these in the pull request.

[huss]

There was only one small merge conflict after the latest PR. I merged in development into this PR so that limitation is now resolved.