_content/doc: update references to obsolete godoc

Updates golang/go#59056

Change-Id: I43ff06556e06c5bd76ee17632d3b316a7fbb7e70
Reviewed-on: https://go-review.googlesource.com/c/website/+/571101
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

_content/doc/cmd.html

@@ -25,9 +25,9 @@
 </p>
 
 <p>
-Finally the <code>fmt</code> and <code>godoc</code> commands are installed
-as regular binaries called <code>gofmt</code> and <code>godoc</code> because
-they are so often referenced.
+The Go installation process also installs an executable
+called <code>gofmt</code>, equivalent to <code>go fmt</code>,
+because it is so often referenced.
 </p>
 
 <p>
@@ -80,9 +80,9 @@
 </tr>
 
 <tr>
-<td><a href="https://godoc.org/golang.org/x/tools/cmd/godoc/">godoc</a></td>
+<td><a href="/cmd/doc">doc</a></td>
 <td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
-<td>Godoc extracts and generates documentation for Go packages.</td>
+<td>Doc extracts and generates documentation for Go packages.</td>
 </tr>
 
 <tr>

_content/doc/install/source.html

@@ -508,8 +508,8 @@ <h2 id="environment">Optional environment variables</h2>
 <p>
 The directory where executables outside the Go distribution are installed
 using the <a href="/cmd/go">go command</a>. For example,
-<code>go install golang.org/x/tools/cmd/godoc@latest</code> downloads, builds,
-and installs <code>$GOBIN/godoc</code>. By default, <code>$GOBIN</code> is
+<code>go install golang.org/x/tools/gopls@latest</code> downloads, builds,
+and installs <code>$GOBIN/gopls</code>. By default, <code>$GOBIN</code> is
 <code>$GOPATH/bin</code> (or <code>$HOME/go/bin</code> if <code>GOPATH</code>
 is not set). After installing, you will want to add this directory to
 your <code>$PATH</code> so you can use installed tools.