Fixed Makefile so it tracks dependencies better

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

src/base.cpp

@@ -0,0 +1,33 @@
+/* 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:
+ */
+
+#include "./base.hpp"
+
+#include <cstdio>
+
+std::optional<std::string> read_file(const char *filename)
+{
+  FILE *fp = fopen(filename, "rb");
+  if (fp)
+  {
+    std::string contents;
+    fseek(fp, 0, SEEK_END);
+    contents.resize(ftell(fp));
+    rewind(fp);
+    fread(&contents[0], 1, contents.size(), fp);
+    fclose(fp);
+
+    return contents;
+  }
+  else
+    return std::nullopt;
+}