Define pre-release ecosystem tests setup

[larsrickert]

Why?

The idea is based on https://github.com/nuxt/ecosystem-ci
Basically: Nuxt updates are run against projects in the Nuxt ecosystem to test for breaking changes or regressions.

Acceptance criteria

• A running PoC was built
• We are able to trigger a run in an Azure DevOps project
• We are able to receive success/failure messages of these runs and display them
  • Check how Nuxt or Vue integrate the results
  • Define how the results are reported and integrated

Definition of Done

• follow-up tickets were created if necessary
• updated version + documentation is deployed
• Set task to In Approval

Approval

• Deployed Docs
• approved by dev

Implementation details

Basic concept:

• Pre-Release triggers Eco-System CI
• Eco-System CI triggers runs (e.g., via web hooks) for registered ecosystems, which in turn report their status back to us

Reference implementations

• https://github.com/nuxt/ecosystem-ci
• https://github.com/vuejs/ecosystem-ci