feat(parser): code syntax highlighting

Signed-off-by: Rongrong <[email protected]>

src/parsing/html_parser.py

@@ -155,7 +155,17 @@ async def _parse_item(self, soup: Union[PageElement, BeautifulSoup, Tag, Navigab
             return Pre(await self._parse_item(soup.children))
 
         if tag == 'code':
-            return Code(await self._parse_item(soup.children))
+            class_ = soup.get('class')
+            if isinstance(class_, list):
+                try:
+                    class_ = next(filter(lambda x: x.startswith('language-'), class_))
+                except StopIteration:
+                    class_ = None
+            elif class_ and isinstance(class_, str) and not class_.startswith('language-'):
+                class_ = f'language-{class_}'
+            else:
+                class_ = None
+            return Code(await self._parse_item(soup.children), param=class_)
 
         if tag == 'br':
             return Br()