Rename LlmConfig to LLMConfig across the codebase to follow consistent naming conventions.
Update all imports and usages to use the new name.
Update documentation and examples to reflect the change.
BREAKING CHANGE: LlmConfig has been renamed to LLMConfig. Users need to update their imports and usage.
* feature: Add LlmConfig to easily configure and pass LLM configs to different strategies
* pulled in next branch and resolved conflicts
* feat: Add gemini and deepseek providers. Make ignore_cache in llm content filter to true by default to avoid confusions
* Refactor: Update LlmConfig in LLMExtractionStrategy class and deprecate old params
* updated tests, docs and readme
