typescript: add kachick as maintainer

pkgs/by-name/ty/typescript/package.nix

···
     homepage = "https://www.typescriptlang.org/";
     changelog = "https://github.com/microsoft/TypeScript/releases/tag/v${finalAttrs.version}";
     license = lib.licenses.asl20;
-    maintainers = [ ];
+    maintainers = with lib.maintainers; [
+      kachick
+    ];
     mainProgram = "tsc";
   };
 })