Include a changelog link for alpha Tor source releases.

This is all cut-and-paste on my part; I do not claim to actually
know Lektor. ;)

templates/download-tor.html

@@ -18,6 +18,7 @@
         {% set a = bag('versions', 'tor-alpha') %}
         {% set download_link = 'https://dist.torproject.org/tor-' + t.version + '.tar.gz' %}
         {% set changelog_link = 'https://gitweb.torproject.org/tor.git/plain/ChangeLog?h=tor-' + t.version %}
+        {% set alpha_changelog_link = 'https://gitweb.torproject.org/tor.git/plain/ChangeLog?h=tor-' + a.version %}
         {% set sig_link = download_link + '.asc' %}
         {% set alpha_download_link = 'https://dist.torproject.org/tor-' + a.version + '.tar.gz' %}
         {% set alpha_sig_link = alpha_download_link + '.asc' %}
@@ -29,6 +30,7 @@
         {% if t.version != a.version %}
           <tr>
             <td>{{ a.version }}</td>
+            <td><a href="{{ alpha_changelog_link }}">{{ _('Changelog') }}</a></td>
             <td class="text-right"><a href="{{ alpha_download_link }}">{{ _('Download') }}</a> (<a href="{{ alpha_sig_link }}">{{ _('sig') }}</a>)</td>
           </tr>
         {% endif %}