[12.x] Be more specific about usage of recycle()

[bertheyman]

Recycle only works for relationships defined inside of the factory.
This PR makes that more clear in the docs, and refers to the hasAttached section for many-to-many relationships.

[shaedrich]

Are you sure, the "one" is supposed to be there?

[shaedrich]

Not sure if the first part is needed since we are already on the "Factories" docs page. Furthermore, I'd assume, you would need yet another line break to make Markdown render the second part as a separate paragraph.

[taylorotwell]

Going to skip this one for now.

[bertheyman]

If you have models that share a common relationship with another model, you may use the recycle method to ensure a single instance of the related model is recycled for all of the relationships created by the factory.

@taylorotwell @shaedrich
I feel the current explanation isn't fully clear: a many-to-many relationships can also be created by the factory, and will not respect recycle(). Would you like me to tweak the wording for this PR, or drop it altogether?

[shaedrich]

I can only speak for myself, but for me, something like this would probably suffice:

> [!NOTE]
> For relationships outside of the factory (like a many-to-many), see [HasAttached()](#pivot-table-attributes).

[bertheyman]

Thanks, good suggestion!
Can't update this PR, so I'll add a new one and see what Taylor thinks.