adds BlackSheep to the list of ASGI web frameworks (#891)

docs/index.md

@@ -481,6 +481,12 @@ with application code still running in a standard threaded context.
 
 You write your API function parameters with Python 3.6+ type declarations and get automatic data conversion, data validation, OpenAPI schemas (with JSON Schemas) and interactive API documentation UIs.
 
+### BlackSheep
+
+[BlackSheep](https://www.neoteroi.dev/blacksheep/) is a web framework based on ASGI, inspired by Flask and ASP.NET Core.
+
+Its most distinctive features are built-in support for dependency injection, automatic binding of parameters by request handler's type annotations, and automatic generation of OpenAPI documentation and Swagger UI.
+
 
 [uvloop]: https://github.com/MagicStack/uvloop
 [httptools]: https://github.com/MagicStack/httptools