Add node documentation for ComfyUI.

web/docs/Retro Diffusion API Node.md

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+# Retro Diffusion API Node
+
+This node enables you to send image generation requests to [Retro Diffusion API](https://retrodiffusion.ai/)
+
+A Retro Diffusion account and API key is required.
+
+## Parameters
+
+- **seed**: The random seed used for Retro Diffusion's inference
+- **width**: The output width in pixels
+- **height**: The output height in pixels
+- **prompt_style**: The [style](https://github.com/Retro-Diffusion/api-examples?tab=readme-ov-file#using-styles) to use from Retro Diffusion
+- **bypass_prompt_expansion**: Disable the prompt expansion that Retro Diffusion applies to your prompt when sending a request
+- **remove_bg**: Enable Retro Diffusion's [background removal](https://github.com/Retro-Diffusion/api-examples?tab=readme-ov-file#using-background-removal-for-transparent-images)
+- **tile_x**: Enable Retro Diffusion's seamless tiling effect along the x-axis
+- **tile_y**: Enable Retro Diffusion's seamless tiling effect along the y-axis
+- **return_spritesheet_for_animations**: Set the output of animation styles to a transparent PNG with the spritesheet instead of a transparent GIF
+- **prompt**: The prompt for the image
+- **denoise**: The amount of denoising applied
+- **input_image**: An optional image used for img2img, or as a reference image for animation styles
+
+## Usage
+
+![example usage](https://github.com/user-attachments/assets/9f2c9634-74e6-4b61-a8f2-6e08132f2f4c)