[docs] Fix outdated links in the documentation (#123)

Author: ldionne

docs/_templates/indexsidebar.html

@@ -1,10 +1,9 @@
 <h3>Install</h3>
 <ul>
-  <li>Install Development release:<br>
-    <tt>pip install svn+http://llvm.org/svn/llvm-project/lnt/trunk</tt></li>
+  <li>Install development snapshot:<br>
+    <tt>pip install git+https://github.com/llvm/llvm-lnt</tt>
+  </li>
 </ul>
 
 <h3>Bugs</h3>
-
-<p>LNT bugs should be reported at the
-  LLVM <a href="https://bugs.llvm.org">Bugzilla</a>.</p>
+<p>LNT bugs should be reported <a href="https://github.com/llvm/llvm-lnt/issues">on GitHub</a>.</p>