cat(1p), true(1p), false(1p): added source files & Makefile

src/true.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023 YAC
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This file is part of YAC coreutils.
+ *
+ * YAC coreutils is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ * 
+ * YAC coreutils is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see https://www.gnu.org/licenses/.
+ */
+
+int main() {}