Improvements for Project Templates

In GitLab 9.5 we introduced Project Templates (#32420 (closed)). The templates are vendored and cannot be changed by users.

This issue is to track possible improvements, based on our vision and on feedbacks (that are already coming).

Proposal

• Squash commits and override author #36899 (moved)
• Custom project templates at the instance level #36943 (closed)

Improvements:

• improve current templates (add more features, as issue templates, default labels, project settings, etc...)
• make templates work smooth with Auto DevOps (#35712 (closed))
• add new templates to the vendored list
• allow predefined templates to be disabled/removed at instance level (#36943 (closed))
• group-level project templates

Links / references

• #32420 (closed)
• #36864 (closed)
• #36836 (closed)
• #36851 (closed)