Allow setting initial commit message on repository creation from template

[KaKi87]

Feature Description

Gitea allows creating new repositories from templates, but the Initial commit message is hard-coded, it would be nice to be able to change it by adding an input in the repo creation form.

Having this feature would allow people who use standard commit messages to follow their standard from the very first commit when starting from a template.

Thanks

Screenshots

No response

[MarkusAmshove]

This would be a nice issue to do together with #11509 which is similar, but for a different message :)

[lunny]

Also related with #18177