[ADD] point_of_sale: documentation for pos-based marketing

[paan-odoo]

This PR adds the documentation needed to use pos-based marketing.

In this PR, we introduce configuration and flow related to Email and WhatsApp marketing in Point of Sale from storing contact details to sending emails and WhatsApp messages from the point of sale.

task- 4053075

[robodoo]

[LoredanaLrpz]

Hi @paan-odoo, thanks so much for your work on this PR! I've been reviewing it and noticed a few areas that might need significant changes. To help move things along, I think it might be best if I make some updates directly and push them to the branch. Would you still like me to share my detailed feedback, or should I focus on the revised version instead? Let me know what you think!

[paan-odoo]

Hello @LoredanaLrpz Yes, I'm fine with that. You can go ahead and push the changes in a separate commit.

Also, Version 18.0 includes additional features that need to be documented. Additionally, there has been a change in the email marketing flow in the master (saas-18.1).

Thanks!

[paan-odoo]

Hello @LoredanaLrpz

I have pushed your suggestions.

Thanks!

[LoredanaLrpz]

The commit I pushed just now is not the PR's final version ;

[LoredanaLrpz]

@robodoo r+