feat: add 'vol' command

programs/src/shell/builtins.cpp

@@ -62,6 +62,7 @@ void cmd_help() {
     montauk::print("  edit [file]     Text editor\n");
     montauk::print("  whoami          Print current username\n");
     montauk::print("  info            Show system information\n");
+    montauk::print("  vol             List mounted volumes\n");
     montauk::print("  date            Show current date and time\n");
     montauk::print("  uptime          Show uptime\n");
     montauk::print("  clear           Clear the screen\n");