dog/go1.14: properly close code tags

Some code tags in the HTML were not properly closed. Close them so that
the text is rendered correctly.

Change-Id: I5c2170ffced313417f65004d53518128c34f7979
Reviewed-on: https://go-review.googlesource.com/c/go/+/200117
Reviewed-by: Ian Lance Taylor <iant@golang.org>

doc/go1.14.html

@@ -54,11 +54,11 @@ <h3 id="go-command">Go command</h3>
 <!-- golang.org/issue/33848 -->
 <p>
   When the main module contains a top-level <code>vendor</code> directory and
-  its <code>go.mod<code> file specifies <code>go</code> <code>1.14</code> or
+  its <code>go.mod</code> file specifies <code>go</code> <code>1.14</code> or
   higher, the <code>go</code> command now defaults to <code>-mod=vendor</code>
   for operations that accept that flag. A new value for that flag,
   <code>-mod=mod</code>, causes the <code>go</code> command to instead load
-  modules from the module cache (as when no <code>vendor<code> directory is
+  modules from the module cache (as when no <code>vendor</code> directory is
   present).
 </p>