Feature : add phpdoc for return types

[momala454]

Can you please add phpdoc so phpstan and other static analyser can know the types

[rkoopmans]

Good idea @momala454 we are on it :-)

[rkoopmans]

I'll close the issue as we are working on it, we will merge level 5 and then move to level 6 #48 thanks for letting us know :-)