flatpak: update metainfo (#5899)

* flatpak: update metainfo

* flatpak: rewrite metainfo

scripts/flatpak/chat.simplex.simplex.metainfo.xml

@@ -38,6 +38,32 @@
   </description>
 
   <releases>
+    <release version="6.3.4" date="2025-05-12">
+      <url type="details">https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html</url>
+      <description>
+        <p>New in v6.3.1-4:</p>
+        <ul>
+          <li>fixes mentions with trailing punctuation (e.g., hello @name!).</li>
+          <li>recognizes domain names as links (e.g., simplex.chat).</li>
+          <li>forward compatibility with "knocking" (a feature for group admins to review and to chat with the new members prior to admitting them to groups, it will be released in 6.4)</li>
+          <li>support for connecting via short connection links.</li>
+          <li>fix related to backward/forward compatibility of the app in some rare cases.</li>
+          <li>scrolling/navigation improvements.</li>
+          <li>faster onboarding (conditions and operators are combined to one screen).</li>
+        </ul>
+        <p>New in v6.3.0:</p>
+        <ul>
+          <li>Mention members and get notified when mentioned.</li>
+          <li>Send private reports to moderators.</li>
+          <li>Delete, block and change role for multiple members at once</li>
+          <li>Faster sending messages and faster deletion.</li>
+          <li>Organize chats into lists to keep track of what's important.</li>
+          <li>Jump to found and forwarded messages.</li>
+          <li>Private media file names.</li>
+          <li>Message expiration in chats.</li>
+        </ul>
+      </description>
+    </release>
     <release version="6.3.3" date="2025-04-24">
       <url type="details">https://simplex.chat/blog/20250308-simplex-chat-v6-3-new-user-experience-safety-in-public-groups.html</url>
       <description>