feat: add AI tools, improve configs, and update README

Changelog:
- Added AI tools and services (Ollama, SearXNG, Open WebUI)
- Updated README with AI tools section and improved formatting
- Added new Rust tools (`cargo-feature`, `cargo-features-manager`)
- Improved virtualisation config with `nvidia-docker`
- Added new work tools (`ssm-session-manager-plugin`, `redli`)
- Updated Helix, Qutebrowser, and Oterm configs
- Added Open WebUI and SearXNG config files

nixos/rust.nix

@@ -24,6 +24,8 @@
     cargo-modules
     cargo-bloat
     cargo-unused-features
+    cargo-feature
+    cargo-features-manager
     bacon
     evcxr #rust repl
   ];