Starter kit relaunch

[thibaudcolas]

Overhaul of the wagtail start support for custom templates and the news template for higher usability and maintainability.

Intended outcome

• Simpler support for multiple starter kits
• Tooling to guarantee starter kits are always up-to-date with latest releases
• Higher usability for developers creating new Wagtail projects
• Better maintainability of official starter templates

More information

• Building a Wagtail starter template
• Wagtail news template