Moved headers to a subdirectory.

src/DString.c

@@ -3,8 +3,8 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "scufcont.h"
-#include "DString.h"
+#include "scufcont/scufcont.h"
+#include "scufcont/DString.h"
 
 ScufContResult SCDString_alloc(SCDString* dstr, const char* str, const size_t len) {
     dstr->data = (char*) malloc(sizeof(char) * (len + 1));

src/scufcont.c

@@ -1,3 +1,3 @@
-#include "scufcont.h"
+#include "scufcont/scufcont.h"
 
 const char* SCUFCONT_VERSION = _SCUFCONT_VERSION;