nixpkgs/neovim: add treesitter for hcl

.config/nixpkgs/neovim/treesitter/grammars.json

@@ -119,5 +119,13 @@
     "rev": "293fdc02038ee2bf0e2e206711b69c90ac0d413f",
     "sha256": "05kk1wlm5fgpgwqxw3m68sipkinw0gf2jq19cgq9cgp3agdwg58p",
     "branch": "v0.25.0^{}"
+  },
+  "hcl": {
+    "repo": "tree-sitter-grammars/tree-sitter-hcl",
+    "rev": "64ad62785d442eb4d45df3a1764962dafd5bc98b",
+    "sha256": "0q6igcw43vdgr5nly7qgblvgw7hvyz4skjsx3lgxkvrnm1kbd7ss",
+    "filetypes": [
+      "terraform"
+    ]
   }
 }