Document how to use fields for navigation properties

[ajcvickers]

See https://github.com/aspnet/EntityFrameworkCore/pull/10939 and https://github.com/aspnet/EntityFrameworkCore/issues/11992

[KshitizGIT]

Does this ticket imply that only documentation part is remaining and the actual functionality is already in EFCore. If so, could you demonstrate some quick codes how to achieve this?

[AndriySvyryd]

@KshitizGIT Yes, if you want to use field-only navigations you can configure them like this:

b.HasMany(typeof(PostNavFields), "_posts").WithOne("_blog");

[ajcvickers]

See also #775