Added instructions on how to access the Swagger API documentation

Author: petak5

README.md

@@ -2,6 +2,11 @@
 
 API backend for [Programming Buddies](https://github.com/ProgrammingBuddies/programmingbuddies-ui) (projects management)
 
+## API documentation
+The documentation is dynamically generated by the server using [Swagger](https://swagger.io) and [Swagger UI](https://swagger.io/tools/swagger-ui/)
+- To view the documentation run the server using one of the set up guides below and then head to `/docs` endpoint
+    - e.g. https://localhost:5001/docs for local development
+
 ## Set up guide: The simple way
 
 - Set up your [environment](#environment)