Component: Sign

This is the component provided by the Sign Upgrade.

Component name: sign.
Callbacks:

• getValue(): string or nil, string
  Gets the text currently displayed on the sign in front of the robot, or nil and an error message if there is no sign in front of the robot.
• setValue(value: string): string or nil, string
  Sets the text of the sign in front of the robot. Returns the new text on the sign (which may be a truncated version of the passed argument) or nil and an error message if there is no sign in front of the robot.