add timezone support, tons of CSS and layout improvements, more detailed snapshot admin form info, ability to sort by recently updated, better grid view styling, better table layouts, better dark mode support

archivebox/main.py

@@ -585,6 +585,7 @@ def add(urls: Union[str, List[str]],
         update_all: bool=not ONLY_NEW,
         index_only: bool=False,
         overwrite: bool=False,
+        # duplicate: bool=False,  # TODO: reuse the logic from admin.py resnapshot to allow adding multiple snapshots by appending timestamp automatically
         init: bool=False,
         extractors: str="",
         parser: str="auto",