Adding user guide to confirmation email

[cielf]

No issue -- follow on from user guide

Description

Adding the user guide to the confirmation email both text and html

Also added text indicating that, while you can use the videos, they are no longer being kept up to date

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Manually checked that the correct html/text is generated and that the link works Added a check that the user guide link is included to the automated texts Ran the tests for the account request email.