alloc big buffers on heap

example/hello.c

@@ -1,7 +1,7 @@
 #include "tim.h"
 
 i32 main(void) {
-    while (tim_run(0)) {                        // event loop
+    while (tim_run(0)) {                        // init state and start event loop
         tim_scope(A, A, 24, 8) {                // centered 24x8 scope
             u64 c = 0x0a060f;                   // three colors
             tim_frame(0, 0, ~0, ~0, c);         // draw frame for scope
@@ -11,5 +11,5 @@ i32 main(void) {
             if (tim_is_key_press('q'))          // ctrl-c is masked
                 return 0;                       // exit on 'q' press
         }
-    }                                           //TODO: remove atexit cleanup
+    }                                           // atexit() cleanup
 }