include notification mp3

add soundnap license

public/i18n/de.json

@@ -191,7 +191,8 @@
         "LICENSES": "Lizenzen",
         "OPEN_SOURCE": "Threema Web ist vollständig Open Source.",
         "SOURCE_CODE": "Der Quellcode und die Lizenzbedingungen finden sich auf Github:",
-        "EMOJI_ART": "Verwendete Emoji stammen von <a href='http://emojione.com'>EmojiOne</a>",
+        "EMOJI_ART": "Verwendete Emoji stammen von <a target=\"_blank\" href=\"http://emojione.com\">EmojiOne</a>",
+        "NOTIFICATION_SOUNDS": "Benachrichtigunstöne &copy; 2012 <a target=\"_blank\" href=\"https://www.soundsnap.com/licence\">soundsnap.com</a> - Licensed under the Soundsnap License",
         "LICENSE_LINK_BEFORE": "Lizenzen von verwendeten Open Source Komponenten können",
         "LICENSE_LINK_TEXT": "im Quellcode",
         "LICENSE_LINK_AFTER": "gefunden werden",

public/i18n/en.json

@@ -192,7 +192,8 @@
         "LICENSES": "Licenses",
         "OPEN_SOURCE": "Threema Web is fully open source.",
         "SOURCE_CODE": "The source code and the licensing terms can be found on Github:",
-        "EMOJI_ART": "Emoji art supplied by <a href='http://emojione.com'>EmojiOne</a>",
+        "EMOJI_ART": "Emoji art supplied by <a target=\"_blank\" href=\"http://emojione.com\">EmojiOne</a>",
+        "NOTIFICATION_SOUND": "Sound files &copy; 2012 <a target=\"_blank\" href=\"https://www.soundsnap.com/licence\">soundsnap.com</a> - Licensed under the Soundsnap License",
         "LICENSE_LINK_BEFORE": "Licenses of used open source components can be found",
         "LICENSE_LINK_TEXT": "in the source code",
         "LICENSE_LINK_AFTER": "",

src/partials/dialog.about.html

@@ -42,6 +42,7 @@
                            target="_blank" rel="noopener noreferrer" translate>about.LICENSE_LINK_TEXT</a>
                         <span translate>about.LICENSE_LINK_AFTER</span>
                     </li>
+                    <li translate>about.NOTIFICATION_SOUND</li>
                 </ul>
 
             </div>