[IMP] rental: revised multi-location section

[fw-bot]

SME requested the following changes:

• Revised the Multi-location management and transfers section to provide a more precise explanation of what the Rental Transfers feature does.
• Added new screenshots, a note, and an example for the section.
• Moved the section closer to the Pickup products section.

Project task: https://www.odoo.com/odoo/action-4043/5351509

This 19.0 PR can be FWP up to master.

Forward-Port-Of: #15436

[robodoo]

[fw-bot]

@meval1006 @StraubCreative this PR targets master and is the last of the forward-port chain.

To merge the full chain, use

@robodoo r+

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port