[Feature] Add color wheel to library

[totally-not-frito-lays]

Is your feature request related to a problem? Please describe.
The Color Wheel Activity is great but after discussion, @innaamogolonova and @totally-not-frito-lays decided that this function is better left blackboxed to the students. We'll migrate this into the library as a dedicated function alternative to the setColor(r,g,b).

Describe the solution you'd like
Implement / copy this into the existing library functions. We'll need changes to these files:

• lantern.h
• lantern.cpp
• keywords.txt
• in library.properties increment version by 0.1.0

Requirements

• The color wheel can accept any number and always output a packed number to result in a color
• There's a corresponding explanation / description in the notion page (dedicated call out block?)
• [Activity] Add color wheel to gradient functions

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  }
  if(WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  }
  WheelPos -= 170;
  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
}

• Source: Adafruit Neopixel Library

Describe alternatives you've considered
We considered leaving the implementation as a written function in examples but this is troublesome because:

• The logic and numbers are not clear or easy for first time programmers
• The point of a wrapper library is to abstract this logic into an easy tool to use

Additional context
Add any other context or screenshots about the feature request here.