I have now figured out how to draw a circle every time the mouse moves
and once the left button is clicked. This uses the
pygame.mouse.get_pressed() to check if the condition is true.

Then if it is it draws a circle for as long as the mouse left click is
held down.

I now have to check how to:

- Get the lines to draw in straight lines only

- Be able to trigger what colour to draw when you click a specific
circle