Supports obtaining PDF documents from web pages (#1107)

### What problem does this PR solve?

Knowledge base management supports crawling information from web pages
and generating PDF documents

### Type of change
- [x] New Feature (Support document from web pages)

requirements.txt

@@ -138,4 +138,6 @@ umap-learn
 fasttext==0.9.2
 volcengine==1.0.141
 readability-lxml==0.8.1
-html_text==0.6.2
+html_text==0.6.2
+selenium==4.21.0
+webdriver-manager==4.0.1