Update factories.rst

[AlaaAttya]

your factory method should be static to work!

[wouterj]

Indeed, the method needs to be static when setting the factory class and it can be non-static when setting a factory service

[weaverryan]

No, it's not quite right yet, unfortunately. If you look at line 80:

When you specify the class to use for the factory (via factory_class)
the method will be called statically. If the factory itself should be instantiated
and the resulting object's method called (as in this example), configure the
factory itself as a service:

So, we're using this one example to explain both factory_class and factory_service. I think we should include this change, but reword this paragraph to something like:

When you specify the class to use for the factory (via factory_class)
the method will be called statically. If the factory itself should be instantiated
and the resulting object's method called, configure the factory itself as a service.
In this case, the method (e.g. get) should be changed to be non-static:

@AlaaAttya Can you make this change please? :)

Thanks!

[AlaaAttya]

@weaverryan done :)

[weaverryan]

Awesome, thanks so much @AlaaAttya!