message: Add redundant documentation to set_relative_mode
  It's not self-evident what relative mode is when visiting the docs (https://docs.rs/ggez/0.4.1/ggez/mouse/fn.set_relative_mode.html). Duplication helps!
diff: @@ -45,6 +45,10 @@ pub fn get_relative_mode(ctx: &Context) -> bool {
  }
  /// Set whether or not the mouse is in relative mode.
  +///
  +/// In relative mode, the cursor is hidden and doesn't move when the mouse
  +/// does, but relative motion events are still generated. This is useful
  +/// for things such as implementing mouselook in an FPS.
  pub fn set_relative_mode(ctx: &Context, mode: bool) {
  ctx.sdl_context.mouse().set_relative_mouse_mode(mode)
  }
  