doc: document go1.8

Change-Id: Ie2144d001c6b4b2293d07b2acf62d7e3cd0b46a7
Reviewed-on: https://go-review.googlesource.com/37130
Reviewed-by: Russ Cox <rsc@golang.org>

doc/devel/release.html

@@ -30,6 +30,13 @@ to fix critical security problems in both Go 1.4 and Go 1.5 as they arise.
 See the <a href="/security">security policy</a> for more details.
 </p>
 
+<h2 id="go1.8">go1.8 (released 2017/02/16)</h2>
+
+<p>
+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>
+
 <h2 id="go1.7">go1.7 (released 2016/08/15)</h2>
 
 <p>

doc/go1.8.html

@@ -15,12 +15,7 @@ Do not send CLs removing the interior tags from such phrases.
 ul li { margin: 0.5em 0; }
 </style>
 
-<h2 id="introduction">DRAFT RELEASE NOTES - Introduction to Go 1.8</h2>
-
-<p><strong>
-Go 1.8 is not yet released. These are work-in-progress
-release notes. Go 1.8 is expected to be released in February 2017.
-</strong></p>
+<h2 id="introduction">Introduction to Go 1.8</h2>
 
 <p>
 The latest Go release, version 1.8, arrives six months after <a href="go1.7">Go 1.7</a>.

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">go1.7.4</code>, for example):</p>
+(<code class="versionTag">go1.8</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">go1.7.4</code>.
+<code class="versionTag">go1.8</code>.
 </p>
 
 <p>