### What problem does this PR solve?
feat: change all file names to lowercase #1574
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
feat: add llm Select to KeywordExtractForm #918
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
feat: add KeywordExtractForm and BaiduForm and DuckDuckGoForm #918
### Type of change
- [x] New Feature (non-breaking change which adds functionality)