[Feat][Java][Doc] Provide document to users and developers

[Thespica]

Is your feature request related to a problem? Please describe.
Java document.

Describe the solution you'd like
It's no doubt that we should provide document to users to teaches how to use GraphAr Java library.

BTW, cause Java rely on C++, we should also make C++ developers realize that their change may affect Java. For details, provide a tutorial to teach how to make related change on Java when Java CI failed.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[Thespica]

Sorry that I remove the assignment with carelessness, I will finish it ASAP.