README.md: Slight name change of argument in documentation about the ScreenHandler.

Author: razterizer

README.md

@@ -162,6 +162,6 @@ You mainly update the screenbuffer by calling `ScreenHandler::write_buffer()` (n
 So a game or application typically calls `write_buffer()` many times in a single frame. It is important to note that you call it in reverse-painter's-algorithm order, which means you write to the buffer in the order of foreground to background,
 e.g. you write your playable character first and then end with scenery such as mountains etc. The reason for this is that every call to `write_buffer()` checks character by character (or tiles, or textels if you will) for already occupying characters before allowing any new characters/tiles/textels to be written into the buffer.
 
-Later in your program - i.e. before the end of the current frame and after all `write_buffer()` calls have been made in that frame - then call `print_screen_buffer(Color clear_bg_color, DrawPolicy policy)`.
+Later in your program - i.e. before the end of the current frame and after all `write_buffer()` calls have been made in that frame - then call `print_screen_buffer(Color clear_bg_color, DrawPolicy posix_redraw_policy)`.
 
  It will make a full redraw or a partial of the screen depending on which policy you've selected. Partial redraw means dirty region-tracking which is achieved by diffing the current screen buffers with the previous frame values. This is in very often faster than a full redraw. When a partial redraw is being made, chunks of contiguous cells/textels/tiles will be drawn using gotorc() and at the end of the frame the frame will be flushed.