add mail_form .gem
welcome Faun
Add feedback form modal

This finishes [#80576984]
Fix failing spec to represent desired behavior
Remove unnecessary specs
fix specs for site_admin
Add fullscreen overlay class

This switches the style of the overlay to white fullscreen
Convert feedback header to H1
tidying, per Riz's feedback
refactor specs for 2 emails: html and text
Merge branch 'master' into feedback-form
last pass styling
add form-control for consistent styling
move capybara specs to quint
tidying
pushing Feedback email and env into the model
Merge pull request #514 from Tahi-project/feedback-form

Feedback form modal in sidebar