doc: document Go 1.9.5

Change-Id: I8f12b188d2e13555e1d7634b9cc0319fc737cb1d
Reviewed-on: https://go-review.googlesource.com/103216Reviewed-by: Ian Lance Taylor <iant@golang.org>

doc/devel/release.html

@@ -81,6 +81,13 @@ See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.9.4">Go
 1.9.4</a> milestone on our issue tracker for details.
 </p>
 
+<p>
+go1.9.5 (released 2018/03/28) includes fixes to the compiler, go command,
+and the <code>net</code> package.
+See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.9.5">Go
+1.9.5 milestone</a> on our issue tracker for details.
+</p>
+
 <h2 id="go1.8">go1.8 (released 2017/02/16)</h2>
 
 <p>