Fixed Makefile so it tracks dependencies better

It now tracks main.cpp's dependencies and rebuilds them as needed.

src/base.hpp

@@ -0,0 +1,21 @@
+/* Copyright (C) 2024 Aryadev Chavali
+
+ * You may distribute and modify this code under the terms of the
+ * GPLv2 license.  You should have received a copy of the GPLv2
+ * license with this file.  If not, please write to:
+ * aryadev@aryadevchavali.com.
+
+ * Created: 2024-04-14
+ * Author: Aryadev Chavali
+ * Description: Base library
+ */
+
+#ifndef BASE_HPP
+#define BASE_HPP
+
+#include <optional>
+#include <string>
+
+std::optional<std::string> read_file(const char *);
+
+#endif