Add Image struct and initialise main arena

src/main.c

@@ -1,4 +1,26 @@
-typedef struct img Image;
-struct img {};
+#include "aliases.h"
+#include "mem_arena.h"
+#include "mem_utils.h"
+#include "pam.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
-int main(void) { return 0; }
+typedef struct img Image;
+struct img {
+  u64 width;
+  u64 height;
+  u8 *buf;
+};
+
+int main(void) {
+  Arena *arena = NULL;
+  if (!wapp_mem_arena_init(&arena, 10ul * 1024ul * 1024ul * 1024ul,
+                           WAPP_MEM_ALLOC_RESERVE, false)) {
+    return -1;
+  }
+
+  wapp_mem_arena_destroy(&arena);
+
+  return 0;
+}