Add PHPDoc for model relationships

[amir9480]

Hello.

I added PHPDoc with return type to model relationships.
It can help code editor provide autocomplete.

[jasonmccreary]

I think this should be good. However, you'll need to rebase and resolve the conflicts.

Also, can you have this honor the blueprint.generate_phpdocs config option as the buildClassPhpDoc does. That way these are only output when this option is true and not by default.

[amir9480]

@jasonmccreary

Hello,
I added blueprint.generate_phpdocs config check and also added a file for unit tests in tests/fixtures/models/relationships-phpdoc.php.

https://github.com/amir9480/blueprint/blob/9120aa353b575a6e53770c75621760fc4e051a90/tests/Feature/Generator/ModelGeneratorTest.php#L226

https://github.com/amir9480/blueprint/blob/add_model_relation_phpdoc/tests/fixtures/models/relationships-phpdoc.php