A small QoL update that lets you pick the color channel used for the Normal Map Generator.

This might let you skip creating a grayscale height map :)

Changelog:

- Added option to pick the channel used for generating Normal Maps

Supported channels: Red, Green, Blue, Gray, Hue, Value (HSV), Lightness (HSL), Saturation (HSL & HSV)

If find any issues or have suggestions, please let me know :)