Add another clothes style/body shape to character randomizer

[wjt]

Threadbare has a character randomizer to create distinct NPCs from a small number of component parts. See it in action in game_elements/characters/components/character_randomizer_test.tscn.

Currently the character randomizer has three body shapes/clothes styles:

One of them is in two parts, I don't know how it works.

We would like more!

The way these are implemented is that there is a sprite sheet for each body in res://scenes/game_elements/characters/npcs/components/, and then a corresponding SpriteFrames in res://scenes/game_elements/characters/components/sprite_frames/, which are added to the RandomTextureSpriteBehavior in res://scenes/game_elements/characters/npcs/townie.tscn. The sprite sheets use three shades of green for the clothes, three shades of yellow for the hands (if visible), plus black outlines. Then, in the game, a chroma-key shader replaces those green/yellow shades with one of a number of alternative palettes. The sprite sheets are exported from a single Aseprite file at scenes/game_elements/characters/npcs/components/townie.aseprite.

So to add a new body style:

1. Open scenes/game_elements/characters/npcs/components/townie.aseprite in Aseprite, Pixelorama or compatible software
2. Add a new body layer
3. Draw a new body using the same palette
4. Export the spritesheet
5. Add a SpriteFrames
6. Update townie.tscn to include it in the randomized choices

@manuq created the existing assets & the game system that uses them, so he is the best person to ask for pointers!

XP Summary (total 450)

Subdomain	Skill	XP
Art: Animation & Effects	Problem Solving	150
Art: Animation & Effects	Creativity & Design Thinking	150
Art: Animation & Effects	Technical Literacy	150