Improvements to Documentation + CPU-only environment

[h-escoffier]

Hello,

I developed WILDkCAT, an pipeline for retrieving kcat data for metabolic model and integrating CataPro to predict kcat values not found in experimental databases.

To simplify installation for new users, I have provided a more detailed tutorial on how to install CataPro.
In the same vein, I have also integrated the changes previously suggested by @JanNiklasWeder, which I also find very useful.

Summary

This PR introduces:

Improvement of the installation guide

• Added a step-by-step installation guide.
• Included missing dependencie sentencepiece
• Added instructions for creating and managing an uv environment.

Fix for CPU-only environments

• Integrates the solution reported by @JanNiklasWeder where CataPro fails to run on systems without CUDA.