feat(cat): add basic cat CLI

Add cat/cat.js which reads a file path from argv and prints the file contents
using node fs promises and top-level await. Logs argv and path (debug output).

Author: Iswanna

implement-shell-tools/cat/cat.js

@@ -0,0 +1,12 @@
+import process from "node:process";
+import { promises as fs } from "node:fs";
+
+const argv = process.argv.slice(2);
+console.log(argv);
+
+const path = argv[0];
+
+console.log(path);
+
+const content = await fs.readFile(path, "utf-8");
+console.log(content.trim());