doc: document go1.8.1

Change-Id: I9282c1907204ec5c6363de84faec222a38300c9f
Reviewed-on: https://go-review.googlesource.com/39919Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

doc/devel/release.html

@@ -30,6 +30,18 @@ Go 1.8 is a major release of Go.
 Read the <a href="/doc/go1.8">Go 1.8 Release Notes</a> for more information.
 </p>
 
+<h3 id="go1.8.minor">Minor revisions</h3>
+
+<p>
+go1.8.1 (released 2017/04/07) includes fixes to the compiler, linker, runtime,
+documentation, <code>go</code> command and the <code>crypto/tls</code>,
+<code>encoding/xml</code>, <code>image/png</code>, <code>net</code>,
+<code>net/http</code>, <code>reflect</code>, <code>text/template</code>,
+and <code>time</code> packages.
+See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.8.1">Go
+1.8.1 milestone</a> on our issue tracker for details.
+</p>
+
 <h2 id="go1.7">go1.7 (released 2016/08/15)</h2>
 
 <p>

doc/install-source.html

@@ -221,7 +221,7 @@ To build without <code>cgo</code>, set the environment variable
 Change to the directory that will be its parent
 and make sure the <code>go</code> directory does not exist.
 Then clone the repository and check out the latest release tag
-(<code class="versionTag">go1.8</code>, for example):</p>
+(<code class="versionTag">go1.8.1</code>, for example):</p>
 
 <pre>
 $ git clone https://go.googlesource.com/go
@@ -409,7 +409,7 @@ New releases are announced on the
 <a href="//groups.google.com/group/golang-announce">golang-announce</a>
 mailing list.
 Each announcement mentions the latest release tag, for instance,
-<code class="versionTag">go1.8</code>.
+<code class="versionTag">go1.8.1</code>.
 </p>
 
 <p>