add integration with the Angel3 framework

[insinfo]

first i would like to thank you for your amazing work on this project, i've been working with dart for 7 years now developing fullstack applications in dart, using AngularDart and Angel Framework, and it's been a lot of pleasure using dart, before i used PHP/C# and javascript, although the dart has fewer tools and libraries with a small ecosystem because it is new, yet it has been very rewarding to work with dart because it is a much less verbose language than C# and PHP, I have contributed to several packages over the years based on what I'm going to need it, I read your article and was happy to see another developer using dart in the backend, dart has a lot of potential for the backend that is still untapped.

I still miss dart backend integration libraries with grafana/prometheus and seeing your work has left me with hope for an integration with Angel3

https://angel3-framework.web.app/#/about https://github.com/dukefirehawk/angel https://github.com/angulardart-community/angular