Update the Vision page as it is outdated

[rcap107]

Describe the issue linked to the documentation

The Skrub Vision page is outdated and should be updated.

It includes as "future developments":

• Add a Join-aggregator object, to do feature augmentation on one-to-many correspondences
• Support polars
• Interpolator join to join across multiple columns without exact correspondences in the keys
• Release (yes we are not planning to release very soon)

Besides removing/updating those points, we should probably add something about the next 6 months.

Suggest a potential alternative/fix

No response