README for new Vector Search structure

[mmahditalachi]

Issue: Update README for new Vector Search structure

Description:
According to the recent changes in VectorSearch and VectorQuery, the README file needs to be updated to reflect the new structure and initialization process.

Task:

Update the README with the latest usage examples for VectorSearch.

Document the new VectorQuery initialization flow.

Ensure backward compatibility notes are included (if any).

[runeanielsen]

Hi @mmahditalachi,

You're welcome to make this change if you want.

// Rune