doc/go1.11: fix some typos

Change-Id: I3c0cb9b56776d8cc78a96ef012385c31f9f0e146
Reviewed-on: https://go-review.googlesource.com/124516Reviewed-by: Austin Clements <austin@google.com>

doc/go1.11.html

@@ -136,13 +136,13 @@ Do not send CLs removing the interior tags from such phrases.
   custom GOPATH trees by other means.
 </p>
 
-<h3 id="gopackages">Package loading</h2>
+<h3 id="gopackages">Package loading</h3>
 
 <p>
   TODO: Note about go/build versus golang.org/x/tools/go/packages.
 </p>
 
-<h3 id="gocache">Build cache requirement</h2>
+<h3 id="gocache">Build cache requirement</h3>
 
 <p>
   Go 1.11 will be the last release to support setting the environment
@@ -162,7 +162,7 @@ Do not send CLs removing the interior tags from such phrases.
 <h3 id="test">Test</h3>
 
 <p>
-  Since Go1.10, the <code>go</code>&nbsp;<code>test</code> command runs
+  Since Go 1.10, the <code>go</code>&nbsp;<code>test</code> command runs
   <code>go</code>&nbsp;<code>vet</code> on the package being tested,
   to identify problems before running the test. Since <code>vet</code>
   typechecks the code with <a href="/pkg/go/types/">go/types</a>