Add link to changelog to about dialog (#176)

public/i18n/de.json

@@ -194,7 +194,11 @@
         "EMOJI_ART": "Verwendete Emoji stammen von <a href='http://emojione.com'>EmojiOne</a>",
         "LICENSE_LINK_BEFORE": "Lizenzen von verwendeten Open Source Komponenten können",
         "LICENSE_LINK_TEXT": "im Quellcode",
-        "LICENSE_LINK_AFTER": "gefunden werden"
+        "LICENSE_LINK_AFTER": "gefunden werden",
+        "CHANGELOG": "Änderungsprotokoll",
+        "CHANGELOG_LINK_BEFORE": "Das Änderungsprotokoll von Threema Web findet sich",
+        "CHANGELOG_LINK_TEXT": "auf Github",
+        "CHANGELOG_LINK_AFTER": "."
     },
     "settings": {
         "SETTINGS":"Einstellungen",

public/i18n/en.json

@@ -195,7 +195,11 @@
         "EMOJI_ART": "Emoji art supplied by <a href='http://emojione.com'>EmojiOne</a>",
         "LICENSE_LINK_BEFORE": "Licenses of used open source components can be found",
         "LICENSE_LINK_TEXT": "in the source code",
-        "LICENSE_LINK_AFTER": ""
+        "LICENSE_LINK_AFTER": "",
+        "CHANGELOG": "Changelog",
+        "CHANGELOG_LINK_BEFORE": "The Threema Web changelog can be found.",
+        "CHANGELOG_LINK_TEXT": "on Github",
+        "CHANGELOG_LINK_AFTER": "."
     },
     "settings": {
         "SETTINGS":"Settings",

src/partials/dialog.about.html

@@ -26,6 +26,13 @@
                        target="_blank" rel="noopener noreferrer">https://github.com/threema-ch/threema-web</a>.
                 </p>
 
+                <h2 translate>about.CHANGELOG</h2>
+                <p>
+                    <span translate>about.CHANGELOG_LINK_BEFORE</span>
+                    <a href="https://github.com/threema-ch/threema-web/blob/master/CHANGELOG.md"
+                       target="_blank" rel="noopener noreferrer" translate>about.CHANGELOG_LINK_TEXT</a><span translate>about.CHANGELOG_LINK_AFTER</span>
+                </p>
+
                 <h2 translate>about.LICENSES</h2>
                 <ul>
                     <li translate>about.EMOJI_ART</li>