Document well lit path for multiple LoRA support

[elevran]

Provided detailed step by steps instructions for working with multiple LoRA's, including all steps and components.
This can be done in llm-d as blog or doc, or upstream in IGW

[elevran]

/assign @davidbreitgand

[davidbreitgand]

@elevran I opened PR in IGW

[elevran]

@nirrozenbaum can we extend this to support using configuration map as source of truth? this can be post v0.4
xref kubernetes-sigs/gateway-api-inference-extension/pull/1812