Add go-llama.cpp backend

shell.nix

@@ -0,0 +1,19 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+let
+  llama = pkgs.llama-cpp;
+in
+pkgs.mkShell {
+  nativeBuildInputs = [
+    pkgs.go
+    pkgs.pkg-config
+  ];
+
+  buildInputs = [ llama ];
+
+  shellHook = ''
+    export CGO_ENABLED=1
+    export CGO_CFLAGS="-I${llama}/include"
+    export CGO_LDFLAGS="-L${llama}/lib -lllama -lm -lstdc++"
+  '';
+}