[vk] parse 'description' metadata (#8029)

gallery_dl/extractor/vk.py

@@ -74,6 +74,8 @@ class VkExtractor(Extractor):
             photo["id"] = photo["id"].rpartition("_")[2]
             photo["date"] = text.parse_timestamp(text.extr(
                 photo["date"], 'data-date="', '"'))
+            photo["description"] = text.unescape(text.extr(
+                photo.get("desc", ""), ">", "<"))
             photo.update(data)
 
             text.nameext_from_url(url, photo)