Update user-facing documentation

[samamou]

How to run onnx models in score

1. Drop a “Process” object (e.g. “BlazePose Detector”) in your timeline.

It can read from a camera or image input texture, run the model, and output results in real-time.

2. Download and load model

• BlazePose model from [Ailia](https://github.com/axinc-ai/ailia-models/tree/master/pose_estimation/blazepose)
  - Download link: https://storage.googleapis.com/ailia-models/blazepose-fullbody/pose_landmark_full.onnx
• Yolov8 pose, download link: https://huggingface.co/Xenova/yolov8-pose-onnx/tree/main#:~:text=yolov8n%2Dpose.onnx,Safe

(until we close [#1701]((in progress: ossia/score#1710

• DONE : add to models to package manager
• [ ]DONE : filter by "AI" category
• add the rest of the models available in the latest release

3. Add an Input camera device (or video)

Choose camera with resolution with the most square ◾ input

• For BlazePose landmark fullbody, change the (input) size to 256 x 256

• TODO: automatically detect input size and pass to connected input camera device ?

4. Add a "Window" device for output

adjust the output size to match the model's output

5. Press play

Add a trigger if you want it to run forever.

General TODO

• Check text from v3.4.0 release https://github.com/ossia/score/releases/tag/v3.4.0
• How to add docs to https://ossia.io/score-docs/processes/ai-recognition.html#blazepose? Where does the content live?