feat(sponsors): Add past sponsors logos (#48)

# Summary:
  - Add sponsor logos to the sponsors page (sponsors.astro) replacing  
  text-only names                                                      
  - Create public/sponsors/ folder for storing company logo assets     

# Desktop:
<img width="1264" height="973" alt="image"
src="https://github.com/user-attachments/assets/a25784b0-515b-4724-82ef-c34788e92e5b"
/>


# Mobile:
<img width="434" height="627" alt="image"
src="https://github.com/user-attachments/assets/5e371ccb-944c-48d1-ac29-84909d58debd"
/>

Author: acabelloj