add <info> key

magic_spoiler/__main__.py

@@ -197,6 +197,14 @@ def open_header(card_xml_file: IO[Any]) -> None:
         + "  \n"
         + "  THIS FILE IS AUTOMATICALLY GENERATED & ALL EDITS WILL BE OVERRIDDEN.\n"
         + "  -->\n"
+        + "<info>\n"
+        + "<author>Cockatrice/Magic-Spoiler</author>\n"
+        #TODO, correct date format
+        + "<createdAt>" + datetime.datetime.utcnow().strftime("%a, %b %d %Y, %H:%M:%S") + "</createdAt>\n"
+        + "<sourceUrl>https://github.com/Cockatrice/Magic-Spoiler/blob/files/spoiler.xml</sourceUrl>\n"
+        #TODO, version schema
+        + "<sourceVersion>???</sourceVersion>\n"
+        + "</info>\n"
         + "<sets>\n"
     )