Mention documentation endpoint

Author: avivace

README.md

@@ -42,5 +42,6 @@ Once started, the backend will expose a number of endpoints:
 - Legacy JQuery web application: [localhost:5000/old](http://localhost:5000/old);
 - API v2: [localhost:5000/v2](http://localhost:5000/v2);
 - New Vue web application: [localhost:5000/](http://localhost:5000/) (assuming a [vue-app](https://github.com/coderbotorg/vue-app) build is placed in the `dist/` folder);
+- Documentation: [localhost:5000/docs](http://localhost:5000/docs) assuming a [docs](https://github.com/coderbotorg/docs) build is placed in the `cb_docs/` folder);
 - Swagger UI dynamic documentation of the API v2: [localhost:5000/v2/ui/index.html](http://localhost:5000/v2/ui/index.html) (once you cloned the [swagger-ui](https://github.com/coderbotorg/swagger-ui) repository inside the backend folder).