Add useful packages to documentation

[Cdayz]

Hi, I made a package to integrate with prometheus, it would be cool if ecosystem packages for blacksheep were mentioned in the documentation.

Package: https://github.com/Cdayz/blacksheep-prometheus PyPI: https://pypi.org/project/blacksheep-prometheus/

[RobertoPrevato]

Hi @Cdayz Thank you! I am working on the documentation these days, and I was going to add a section for external packages. I will surely add yours to the list.

[Cdayz]

Hi, I'm on a roll today, I made another useful package for blacksheep - blacksheep-context. Package: https://github.com/Cdayz/blacksheep-context PyPI: https://pypi.org/project/blacksheep-context/

[myusko]

Hi @Cdayz These packages look awesome! Thank you for your hard work.