Docs: Add Section on MikroORM Listeners Gotchas

[thekevinbrown]

Describe the bug

Some of the stuff that Mikro-Orm says to do seems to crash Graphweaver. For instance, I followed a guide from Mikro-Orm to setup an event subscriber with the intent of using that to listen to all CRUD operations and send websocket the messages rather than duplicating that code across the various entity hooks. However, when I implemented it, it triggered the events as expected, however it never returns the payload.

MikroORM listeners are quite low level, and they do work with Graphweaver, but we should provide some examples as to what you can / can't do with them.

Additional context
https://graphweaver.slack.com/archives/D0730MYM74Z/p1726103546839589?thread_ts=1723672001.215299&cid=D0730MYM74Z