[docs] Provide detailed instructions for developers and contributors of CUDA-Q

[khalatepradnya]

Required prerequisites

• Search the issue tracker to check if your feature has already been mentioned or rejected in other issues.

Describe the feature

Update https://github.com/NVIDIA/cuda-quantum/blob/main/Developing.md to provide instructions on building, rebuilding, running tests (C++, Python, unittests, integration tests), formatting code, running spell checks.