feat(highlight): add nix syntax highlighting (#6386)

packages/opencode/parsers-config.ts

@@ -235,5 +235,19 @@ export default {
         ],
       },
     },
+    {
+      filetype: "nix",
+      // TODO: Replace with official tree-sitter-nix WASM when published
+      // See: https://github.com/nix-community/tree-sitter-nix/issues/66
+      wasm: "https://github.com/ast-grep/ast-grep.github.io/raw/40b84530640aa83a0d34a20a2b0623d7b8e5ea97/website/public/parsers/tree-sitter-nix.wasm",
+      queries: {
+        highlights: [
+          "https://raw.githubusercontent.com/nvim-treesitter/nvim-treesitter/refs/heads/master/queries/nix/highlights.scm",
+        ],
+        locals: [
+          "https://raw.githubusercontent.com/nvim-treesitter/nvim-treesitter/refs/heads/master/queries/nix/locals.scm",
+        ],
+      },
+    },
   ],
 }