fix: time zone info is now shown

datetime.now() produces a naive datetime object which does not know tzinfo. 
So the '%z' has no effect. We need to convert it to time zone aware object using
`datetime.astimezone()`.

my_snippets/markdown.snippets

@@ -20,7 +20,7 @@ snippet "meta(data)?" "Markdown front matter in YAML format" br
 title: "$1"
 date: `!p from datetime import datetime
 if not snip.c:
-	snip.rv=datetime.now().strftime("%Y-%m-%d %H:%M:%S%z")`
+	snip.rv=datetime.now().astimezone().strftime("%Y-%m-%d %H:%M:%S%z")`
 tags: [$2]
 categories: [$3]
 ---