EntityType's by_reference option undocumented

[Herz3h]

I have a OneToMany relation, and I struggled for 30 mins because my changes on the One side weren't not persisted.

It turns out, adding by_reference makes it work, but is undocumented:

https://symfony.com/doc/4.4/reference/forms/types/entity.html

[carsonbot]

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?

[carsonbot]

Hello? This issue is about to be closed if nobody replies.

[Herz3h]

I have sent a PR to document this