chore: add resource under cpp:libraries:poco

src/data/roadmaps/cpp/content/libraries/102-poco.md

@@ -69,3 +69,5 @@ int main()
 ```
 
 In the above example, Poco is used to send an HTTP GET request and process the response. It manages tasks like connecting to the server, handling exceptions, and managing HTTP headers.
+
+- [Official Docs for Poco Library](https://docs.pocoproject.org/)