Credit some heavy-lifting dependencies in the readme. (#17)

Author: kentonv

README.md

@@ -237,3 +237,12 @@ With that said, we are happy to accept small, trivially-verified PRs that fix a
 If you have a big idea you'd like us to consider, feel free to [open a discussion](https://github.com/cloudflare/cloudflare-os/discussions) about it.
 
 This policy may change in the future as the project matures. Until then, thank you for your understanding.
+
+## Credits
+
+Cloudflare OS has far too many open source dependencies to list here. But, we'd like to highlight a few that do particularly heavy lifting:
+
+* [Pi](https://pi.dev/) (specifically, `pi-agent-core`), which made it easy to support every LLM provider with one API.
+* [Monaco](https://microsoft.github.io/monaco-editor/) which makes it too easy to embed a beautiful text editor -- for those of us who still look at the code.
+* [Yjs](https://yjs.dev/), which we use extensively to sync code changes between clients and agents and replay histories.
+* [Vite](https://vite.dev/), which makes the development loop so pleasant.