doc: add Belarusian FAQ translation

R=golang-dev, dchest
CC=golang-dev
https://golang.org/cl/4564057

doc/docs.html

@@ -59,6 +59,12 @@ An introduction to Go for C++ programmers.
 
 <h2 id="tutorials_nonenglish">Non-English Documentation</h2>
 
+<h3 id="docs_be">Belarusian &mdash; Беларуская</h3>
+
+<ul>
+<li><a href="http://www.designcontest.com/show/faq-be">faq-be</a> - Frequently Asked Questions.</li>
+</ul>
+
 <h3 id="docs_cn">Chinese &mdash; 中文</h3>
 
 <ul>