doc/go1.11: fix unclosed html and typos in net section

Change-Id: I3bcf8850ad3873f2627ba017cbfb8b7a8c9cf467
Reviewed-on: https://go-review.googlesource.com/125256Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

doc/go1.11.html

@@ -596,9 +596,9 @@ for k := range m {
     <p><!-- CL 107715 -->
       The <code>net</code> package now automatically uses the
       <a href="http://man7.org/linux/man-pages/man2/splice.2.html"><code>splice</code> system call</a>
-      on Linux when calling copying data between TCP connections in
+      on Linux when copying data between TCP connections in
       <a href="/pkg/net/#TCPConn.ReadFrom"><code>TCPConn.ReadFrom</code></a>, as called by
-      <a href="/pkg/io/#Copy"><code>io.Copy</code>. The result is faster, more efficient TCP proxying.
+      <a href="/pkg/io/#Copy"><code>io.Copy</code></a>. The result is faster, more efficient TCP proxying.
     </p>
 
     <p><!-- CL 108297 -->
@@ -623,7 +623,7 @@ for k := range m {
 
     <p><!-- CL 79919 -->
       The <a href="/pkg/net/http/#Cookie"><code>Cookie</code></a> type has a new
-      The <a href="/pkg/net/http/#Cookie.SameSite"><code>SameSite</code></a> field
+      <a href="/pkg/net/http/#Cookie.SameSite"><code>SameSite</code></a> field
       (of new type also named
       <a href="/pkg/net/http/#SameSite"><code>SameSite</code></a>) to represent the new cookie attribute recently supported by most browsers.
       The <code>net/http</code>'s <code>Transport</code> does not use the <code>SameSite</code>