added ollama support with configurable base URL

[KPR-V]

This pull request introduces the integration of the Ollama provider into the SDK and updates the documentation to reflect this new feature. The main changes include adding the Ollama configuration type, handling the Ollama provider in the LLM class, and updating the README with usage instructions.

Integration of Ollama provider:

• packages/ai-agent-sdk/src/core/llm/index.ts: Added OllamaModel type and OllamaConfig type to support the Ollama provider. Updated ModelConfig to include OllamaConfig.
• packages/ai-agent-sdk/src/core/llm/index.ts: Modified the LLM class to handle the Ollama provider, setting the baseURL from the environment variable or defaulting to http://localhost:11434.

Documentation updates:

• README.md: Added a new section "Using Ollama with the SDK" with an example configuration for setting up an agent with the Ollama provider.

[KPR-V]

this is the sample image of the response
this image above has the result
and below the result.messages[result.messages.length - 1]?.content