i18n: fix pignus translation for transifex

dist/templates/about/usage.html.hbs

@@ -55,7 +55,7 @@
     <p>
         Note that there is no built-in support for upload and email address verification so far.
     </p>
-	
+
     <h2>
         <div><img src="/assets/img/pignus.png"></div>
         Pignus

templates-untranslated/about/usage.html.hbs

@@ -55,6 +55,20 @@
         Note that there is no built-in support for upload and email address verification so far.
     </p>
 
+    <h2>
+        <div><img src="/assets/img/pignus.png"></div>
+        Pignus
+    </h2>
+    <p>
+        <a href="https://www.frobese.de/pignus/">Pignus</a> for iOS
+        uses <span class="brand">keys.openpgp.org</span> by default
+        since November 2019.
+        <ul>
+            <li>Your keys can be uploaded at any time.</li>
+            <li>Keys can be discovered by email address.</li>
+        </ul>
+    </p>
+
     <h2>
         <div><img src="/assets/img/gnupg.svg" /></div>
         GnuPG