Evaluate and potentially redesign layout of emails sent from Gitea

[acn-sbuad]

Description

Design part of #764 extracted into seperate issue.
Consider texts and the layout of the emails sent by gitea, should they be made more Altinn ish?

Emails support html so we can be relatively creative if we wish to be so.

Doc on mail templates

Screenshots

Screenshots or links to Figma (make sure your sketch is public)

Considerations

Describe input (beyond tasks) on how the user story should be solved can be put here.

Acceptance criteria

Describe criteria here (i.e. What is allowed/not allowed (negative tesing), validations, error messages and warnings etc.)

Specification tasks

• Evaluate current layout and texts
• Create design for new templates
• Create development tasks

Development tasks

• QA
• Manual test is complete (if relevant)

[6543]

Be aware of go-gitea/gitea#16200 who will be shiped with gitea v1.15.0

The easyset way to customize would be to enhance/add css in template header...