Add line_t struct and update draw_line function

include/rasteriser/rasteriser.h

@@ -4,6 +4,11 @@
 #include "vector/vec.h"
 #include "window/window.h"
 
-void draw_line(window_t *wnd, vec2i_t p0, vec2i_t p1, colour_t colour);
+typedef struct {
+  vec2i_t p0;
+  vec2i_t p1;
+} line_t;
+
+void draw_line(window_t *wnd, line_t line, colour_t colour);
 
 #endif // !RASTERISER_H