API: updated files to use new folder setup

src/filters.c

@@ -3,7 +3,7 @@
 #include <stdlib.h>
 
 // #include "utils.h"
-#include "filters.h"
+#include "image/filters.h"
 
 unsigned int
 u32_put_alpha(const unsigned int clr, const unsigned char alpha)

src/imgio.c

@@ -1,4 +1,4 @@
-#include "imgio.h"
+#include "image/imgio.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <turbojpeg.h>

src/transformations.c

@@ -1,5 +1,5 @@
 #include <stdlib.h>
-#include "transformations.h"
+#include "image/transformations.h"
 
 unsigned int*
 ppm_flip_h(const unsigned int* buf, const PPM img)

src/utils.c

@@ -1,4 +1,4 @@
-#include "utils.h"
+#include "image/utils.h"
 
 unsigned long
 u32to_u64(const unsigned int clr)