PicoVector: Add declaration for pp_contour_bounds.

libraries/pico_vector/pico_vector.hpp

@@ -2,6 +2,8 @@
 #include "alright_fonts.hpp"
 #include "pico_graphics.hpp"
 
+pp_rect_t pp_contour_bounds(const pp_path_t *c);
+
 namespace pimoroni {
 
     // Integer point types cause compound error in transformations