[readme] include link to related resources (#736)

README.md

@@ -13,6 +13,9 @@ Example code and guides for accomplishing common tasks with the [OpenAI API](htt
 
 Most code examples are written in Python, though the concepts can be applied in any language.
 
+For other useful tools, guides and courses, check out these [related resources from around the web](https://cookbook.openai.com/related_resources).
+
+
 ## Contributing
 
 The contents of this repo are automatically rendered into [cookbook.openai.com](https://cookbook.openai.com). If there are examples or guides you'd like to see, feel free to suggest them on the [issues page](https://github.com/openai/openai-cookbook/issues). We are also happy to accept high quality pull requests, as long as they fit the scope of the cookbook.