[kemonoparty] add 'announcements' option (#5262)

https://github.com/mikf/gallery-dl/issues/5262#issuecomment-2015919188

test/results/kemonoparty.py

@@ -135,6 +135,19 @@ __tests__ = (
     }],
 },
 
+{
+    "#url"     : "https://kemono.su/patreon/user/3161935/post/68231671",
+    "#comment" : "announcements",
+    "#category": ("", "kemonoparty", "patreon"),
+    "#class"   : kemonoparty.KemonopartyPostExtractor,
+    "#options" : {"announcements": True},
+
+    "announcements": [{
+        "body": "<div><strong>Thank you so much for the support!</strong><strong><br></strong>This Patreon is more of a tip jar for supporting what I make. I have to clarify that there are <strong>no exclusive Patreon animations</strong> because all are released for the public. You will get earlier access to WIPs. Direct downloads to my works are also available for $5 and $10 Tiers.</div>",
+        "date": "2023-02",
+    }],
+},
+
 {
     "#url"     : "https://kemono.su/patreon/user/19623797/post/29035449",
     "#comment" : "invalid file (#3510)",