Add link to GitHub from menu

_includes/header.html

@@ -29,6 +29,7 @@
             <li><a href="/getting-started/donate">{% t menu.donations %}</a></li>
             <li class="divider"></li>
             <li><a href="/downloads">{% t menu.downloads %}</a></li>
+            <li><a href="https://github.com/monero-project">{% t menu.github %}</a></li>
             <li class="divider"></li>
             <li><a href="/getting-started/accepting">{% t menu.accepting %}</a></li>
             <li><a href="/getting-started/merchants">{% t menu.merchants %}</a></li>

_strings_en.yml

@@ -30,6 +30,7 @@ menu:
   donations: Donating and Sponsorships
   contribute: Contributing to Monero
   downloads: All Monero Downloads
+  github: GitHub
   merchants: Merchants and Services Directory
   accepting: Accepting Monero Payments
   about: About Monero