add docs translated to russian - patch from Pavel Luzanov on -www

pgweb/util/contexts.py

@@ -36,6 +36,7 @@ sitenav = {
 			{'title': 'Archive',    'link':'/docs/manuals/archive/'},
 			{'title': 'French',     'link':'http://docs.postgresqlfr.org/'},
 			{'title': 'Japanese',   'link':'http://www.postgresql.jp/document/'},
+			{'title': 'Russian',    'link':'https://postgrespro.ru/docs'},
 		]},
 		{'title': 'Security',           'link':'/support/security/'},
 		{'title': 'What\'s New',        'link':'/docs/current/static/release.html'},

templates/docs/index.html

@@ -32,6 +32,7 @@ written about PostgreSQL (some of which are available in their entirety online).
         <ul>
           <li><a href="http://docs.postgresql.fr">French</a></li>
           <li><a href="http://www.postgresql.jp/document/">Japanese</a></li>
+          <li><a href="https://postgrespro.ru/docs">Russian</a></li>
         </ul>
     </dd>
     <dd><p></p><a href="/docs/manuals">More manuals</a></dd>