Add `!upload_image` WIP

[rockerBOO]

!upload_image URL will download the image, remove the background, and resize into a 256x256 image size (by the largest dimension, and keeping the aspect ratio).

Needs

• curl
• rembg in your path
• imagemagick (convert)

curl -s {} | rembg i > output.png
convert output.png -resize 256x256^ {}

[rockerBOO]

This is not going as planned.