rosenthal: Add tree-sitter-cmake.

* rosenthal/packages/tree-sitter.scm: New file.
(tree-sitter-grammar,tree-sitter-cmake): New variables.

rosenthal/packages/tree-sitter.scm

@@ -0,0 +1,13 @@
+(define-module (rosenthal packages tree-sitter)
+  #:use-module (guix packages))
+
+(define tree-sitter-grammar
+  (@@ (gnu packages tree-sitter) tree-sitter-grammar))
+
+;; <https://issues.guix.gnu.org/64430>
+(define-public tree-sitter-cmake
+  (tree-sitter-grammar
+   "cmake" "CMake"
+   "0i8vsvkkas1fnn35na68gq5xq2y3xvhv2bk9q6x8c1bzsqm6rcsa"
+   "0.4.0"
+   #:repository-url "https://github.com/uyha/tree-sitter-cmake"))