docs: move Credits to monorepo README, remove from submodules

README.md

@@ -61,3 +61,16 @@ git submodule update --remote
 - `tui/`: Terminal UI (Go)
 - `9p/`: 9p filesystem server (Go)
 - `el/`: Emacs Lisp interface (Emacs Lisp)
+## Credits
+
+Many sources of inspiration:
+
+- [Plan 9 from Bell Labs](https://9fans.net) — for an interesting system
+- [@9fans](https://github.com/9fans) — for the Plan 9 port
+- [Suckless](https://suckless.org) — for articulating good software development principles
+- [@simonfxr](https://github.com/simonfxr) — for a solid agent baseline to "borrow" from, and other nifty ideas
+- [@aws](https://github.com/aws/amazon-q-developer-cli) — for a solid open-source agent implementation
+
+## License
+
+GPLv3