feat(build): use meson so I don't end up ripping my hair out

include/utils.h

@@ -1,2 +1,20 @@
+#pragma once
+
+/**
+ * @brief get a substring of a string
+ *
+ * @param s string
+ * @param pos first pos
+ * @param l length
+ * @return the substring
+ */
 char *get_substring(char *s, int pos, int l);
+
+/**
+ * @brief concatinate two strings
+ *
+ * @param s1 first
+ * @param s2 second
+ * @return the concatinated string
+ */
 char *concat(const char *s1, const char *s2);