docs: Clarify warning about metadata in inline projections

[thomaslevesque]

This limitation no longer applies, according to #3431 (comment)

[jeremydmiller]

@thomaslevesque Actually needs more context rather than removing that. That is long, long obsolete if you use the Rich Append mode (the default), but goes back to being true if opting into the faster "quick append" mode.

https://www.youtube.com/watch?v=CQeezCdF4mk

[thomaslevesque]

@jeremydmiller ah, I see, thanks.
So, if I understand this correctly, the IEvent.Version and IEvent.Sequence aren't available in inline projections when using "Quick" append mode, but the rest of the metadata is available?

[jeremydmiller]

@thomaslevesque Correct. All about compromises. The "rich append" mode was put in place for Marten 4 because people wanted to use the event sequence and stream version data in inline projections, but it turns out that comes with a big perf cost, potentially causes a lot of concurrency issues, and makes the async daemon more prone to skipping events. So back came the <=3.0 "quick append" behavior.

Except just to make it more complicated, the new quick append method can at least use the correct stream version within aggregates stored in the database along the way. The event sequence is only assigned at the time the events are persisted though.

[thomaslevesque]

OK, thanks for the explanation. I'll try to reword the warning to make things clearer

[jeremydmiller]

@thomaslevesque Thank you for taking this on!

[thomaslevesque]

@jeremydmiller is that better?

[mysticmind]

@thomaslevesque the changes look fine.