Update release appcast for 6.1.5.

Appcasts/netnewswire-release.xml

@@ -6,7 +6,25 @@
         <description>Most recent NetNewsWire releases (not test builds).</description>
         <language>en</language>
 
-        <item>
+       <item>
+            <title>NetNewsWire 6.1.5</title>
+            <description><![CDATA[
+            <ul>
+				<li>Restore toggle sidebar button to toolbar</li>
+				<li>Add keyboard shortcut for Copy Article URL and Copy External URL menu items</li>
+				<li>Fix some Applescript bugs</li>
+				<li>Add support for 429 responses and Cache-Control header — will use less bandwidth and will be kinder to servers (for On My Mac and iCloud accounts)</li>
+				<li>Fix a bug with conditional GET support</li>
+				<li>Support MarsEdit 5 - it will now appear in Share menu</li>
+				<li>Fix a crashing bug that could happen when adding an account</li>
+            </ul>
+            ]]></description>
+            <pubDate>Mon, 03 Dec 2024 20:35:00 -0800</pubDate>
+            <enclosure url="https://github.com/Ranchero-Software/NetNewsWire/releases/download/mac-6.1.5/NetNewsWire6.1.5.zip" sparkle:version="6126" sparkle:shortVersionString="6.1.5" length="9809467" type="application/zip" />
+            <sparkle:minimumSystemVersion>13.0.0</sparkle:minimumSystemVersion>
+       </item>
+
+       <item>
             <title>NetNewsWire 6.1.4</title>
             <description><![CDATA[
             <p>Reddit API integration has ended as of June 30, 2023, due to Reddit CEO Steve Huffman’s decision to make apps like NetNewsWire pay to use the Reddit API.</p>