Multilora docs

[natke]

Staged here:

• Tutorial: https://natke.github.io/onnxruntime/docs/genai/tutorials/finetune.html
• Python API docs: https://natke.github.io/onnxruntime/docs/genai/api/python.html#adapter-class
• C API docs: https://natke.github.io/onnxruntime/docs/genai/api/c.html#adapter-api
• C# API docs: https://natke.github.io/onnxruntime/docs/genai/api/csharp.html#adapter-class
• Java API docs: https://natke.github.io/onnxruntime/docs/genai/api/java.html#adapter-class ;-)
• Adapter file format reference: https://natke.github.io/onnxruntime/docs/genai/reference/adapter.html