0.4.0

## Highlights

- Support [Evaluation (beta)](https://tidb.ai/docs/evaluation) tool to evaluate the performance and reliability of the Chat Engine’s outputs  (by @Icemap @634750802 ).
  - Current support key metrics:
    - Factual Correctness
    - Semantic Similarity
- Support new LLM providers
  - [Gitee AI](https://tidb.ai/docs/llm#gitee-ai) (by @lc-soft)
  - Test new OpenAI-like providers (by @jrj5423)
    - [vLLM](https://tidb.ai/docs/llm#vllm)
    - [Xinference](https://tidb.ai/docs/llm#xinference)
- Support new embedding model providers
  - [Gitee AI](https://tidb.ai/docs/embedding-model#gitee-ai) (by @lc-soft)
  - [Amazon Bedrock](https://tidb.ai/docs/embedding-model#amazon-bedrock) (by  @jrj5423 @Mini256)

## Improvements

- Limit the upload file size via `max_upload_file_size` (10MB by default) parameter on site setting (by @sszgwdk @634750802 )
- Support download the reference file in the chat page (by @Rutheniumlmw @634750802 )

## New Contributors

* @sszgwdk made their first contribution in https://github.com/pingcap/autoflow/pull/497
* @jrj5423 made their first contribution in https://github.com/pingcap/autoflow/pull/522
* @Rutheniumlmw made their first contribution in https://github.com/pingcap/autoflow/pull/538
* @lc-soft made their first contribution in https://github.com/pingcap/autoflow/pull/470
* @nicognaW made their first contribution in https://github.com/pingcap/autoflow/pull/496

If you are deploying Autoflow using docker, please follow the [Upgrade](https://tidb.ai/docs/deploy-with-docker#upgrade) guide to upgrade your Autoflow.

**Full Changelog**: https://github.com/pingcap/autoflow/compare/v0.3.0...0.4.0