updates documentation

- using material theme instead of readthedocs
- introducing "Interacting with pydase Services" guide
    - restful api docs
    - auto-generated frontend
    - pydase.Client

docs/user-guide/interaction/RESTful API.md

@@ -0,0 +1,14 @@
+# RESTful API
+
+The `pydase` RESTful API allows for standard HTTP-based interactions and provides access to various functionalities through specific routes. This is particularly useful for integrating `pydase` services with other applications or for scripting and automation.
+
+To help developers understand and utilize the API, we provide an OpenAPI specification. This specification describes the available endpoints and corresponding request/response formats.
+
+## OpenAPI Specification
+**Base URL**:
+
+```
+http://<hostname>:<port>/api/
+```
+
+<swagger-ui src="./openapi.yaml"/>