[ADD] events: lead generation rules (17)

[ksc-odoo]

PROJECT TASK: https://www.odoo.com/web#id=3939026&cids=3&menu_id=4720&action=333&active_id=3835&model=project.task&view_type=form

This PR will solely focus on how to create Lead Generation Rules in the Odoo Events application.
Currently, there is only a minor mention of this functionality at the bottom of the outdated track and manage talks doc (which has already been updated; awaiting publication)

[robodoo]

Pull request status dashboard.

[ksc-odoo]

Hey @jero-odoo -- this one is ready for a Peer Review, whenever you get a chance. Thanks!

[jero-odoo]

Hey @ksc-odoo great work on this one, really informative 👍 Most of my notes are optional, so I am approving this for the next round.
One thing to note, in the Sample reul section, there is some switching between pov (sometimes it is written as "the company does this" vs "click here" instructions). That may need a second look just for consistency's sake. Otherwise, looks great! Let me know if you have any questions. Thanks!

[ksc-odoo]

hey, @jero-odoo 👋 Thank you SO much for all the awesome feedback. I implemented all your suggested changes, and made sure to rework the sample portion at the end to establish a more uniform POV for the reader. That said, I believe this one is now ready for a Final Review, @StraubCreative -- whenever you get a chance. Thanks! 🙏

[StraubCreative]

@ksc-odoo I haven't fully reviewed yet, but this part stuck out to me on quick look.

I'm not sure there's a relevant use case here to create a rule like this since Attendees by Source is more of a reporting filter which can be done right from the Attendees tab in the Events app.

To give readers a working success model, consider covering how we internally set up LGRs for the Events team— the rules we have set up are pretty in-depth and really cover the functionality quite nicely ^^

Please remind me I can show you what I mean, if you like!