Update AppStream metainfo.xml.

org.electrum.electrum.metainfo.xml

@@ -1,5 +1,11 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Copyright 2013 Soren Stoutner <soren@stoutner.com> -->
+
+<!--
+  Copyright 2023-2024 Soren Stoutner <soren@debian.org>.
+
+  This file can be validated using `appstreamcli validate org.electrum.electrum.metainfo.xml`.
+-->
+
 <component type="desktop-application">
   <id>org.electrum.electrum</id>
 
@@ -11,11 +17,16 @@
 
   <description>
     <p>
-      Electrum is a lightweight Bitcoin wallet focused is speed, with low resource usage and simplifying Bitcoin.
+      Electrum is a lightweight Bitcoin wallet focused on speed, with low resource usage and simplifying Bitcoin.
       Startup times are instant because it operates in conjunction with high-performance servers that handle the most complicated parts of the Bitcoin system.
     </p>
   </description>
 
+  <url type="homepage">https://www.electrum.org/</url>
+  <developer id="org.electrum">
+      <name>The Electrum developers</name>
+  </developer>
+
   <launchable type="desktop-id">electrum.desktop</launchable>
 
   <content_rating type="oars-1.1" />