Add official external commands to manpage.

These are the ones that are auto-installed without tapping and it makes
sense to make them more prominent in our documentation as we've
offloaded various functionality over the years to each of them.

Library/Homebrew/manpages/brew.1.md.erb

@@ -54,7 +54,21 @@ With `--verbose` or `-v`, many commands print extra debugging information. Note
 
 <%= developer_commands.join("\n") %>
 
-## EXTERNAL COMMANDS
+## OFFICIAL EXTERNAL COMMANDS
+
+  * `bundle`:
+    Bundler for non-Ruby dependencies from Homebrew:
+    <https://github.com/Homebrew/homebrew-bundle>
+
+  * `cask`:
+    Install macOS applications distributed as binaries:
+    <https://github.com/caskroom/homebrew-cask>
+
+  * `services`:
+    Integrates Homebrew formulae with macOS's `launchctl` manager:
+    <https://github.com/Homebrew/homebrew-services>
+
+## CUSTOM EXTERNAL COMMANDS
 
 Homebrew, like `git`(1), supports external commands. These are executable
 scripts that reside somewhere in the `PATH`, named `brew-`<cmdname> or
@@ -251,7 +265,7 @@ If your proxy requires authentication:
 
 Homebrew Documentation: <https://github.com/Homebrew/brew/blob/master/docs/>
 
-`git`(1), `git-log`(1)
+`brew-cask`(1), `git`(1), `git-log`(1)
 
 ## AUTHORS
 

docs/brew.1.html

@@ -601,7 +601,19 @@ the new repository clone.</p></dd>
 </dl>
 
 
-<h2 id="EXTERNAL-COMMANDS">EXTERNAL COMMANDS</h2>
+<h2 id="OFFICIAL-EXTERNAL-COMMANDS">OFFICIAL EXTERNAL COMMANDS</h2>
+
+<dl>
+<dt class="flush"><code>bundle</code></dt><dd><p>Bundler for non-Ruby dependencies from Homebrew:
+<a href="https://github.com/Homebrew/homebrew-bundle" data-bare-link="true">https://github.com/Homebrew/homebrew-bundle</a></p></dd>
+<dt class="flush"><code>cask</code></dt><dd><p>Install macOS applications distributed as binaries:
+<a href="https://github.com/caskroom/homebrew-cask" data-bare-link="true">https://github.com/caskroom/homebrew-cask</a></p></dd>
+<dt><code>services</code></dt><dd><p>Integrates Homebrew formulae with macOS's <code>launchctl</code> manager:
+<a href="https://github.com/Homebrew/homebrew-services" data-bare-link="true">https://github.com/Homebrew/homebrew-services</a></p></dd>
+</dl>
+
+
+<h2 id="CUSTOM-EXTERNAL-COMMANDS">CUSTOM EXTERNAL COMMANDS</h2>
 
 <p>Homebrew, like <code>git</code>(1), supports external commands. These are executable
 scripts that reside somewhere in the <code>PATH</code>, named <code>brew-</code><var>cmdname</var> or
@@ -742,7 +754,7 @@ your shell profile, or you can use it before a brew command:</p>
 
 <p>Homebrew Documentation: <a href="https://github.com/Homebrew/brew/blob/master/docs/" data-bare-link="true">https://github.com/Homebrew/brew/blob/master/docs/</a></p>
 
-<p><code>git</code>(1), <code>git-log</code>(1)</p>
+<p><code>brew-cask</code>(1), <code>git</code>(1), <code>git-log</code>(1)</p>
 
 <h2 id="AUTHORS">AUTHORS</h2>
 

manpages/brew.1

@@ -801,7 +801,21 @@ If \fB\-\-to\-tag\fR is passed, set HOMEBREW_UPDATE_TO_TAG to test updating betw
 .IP
 If \fB\-\-keep\-tmp\fR is passed, retain the temporary directory containing the new repository clone\.
 .
-.SH "EXTERNAL COMMANDS"
+.SH "OFFICIAL EXTERNAL COMMANDS"
+.
+.TP
+\fBbundle\fR
+Bundler for non\-Ruby dependencies from Homebrew: \fIhttps://github\.com/Homebrew/homebrew\-bundle\fR
+.
+.TP
+\fBcask\fR
+Install macOS applications distributed as binaries: \fIhttps://github\.com/caskroom/homebrew\-cask\fR
+.
+.TP
+\fBservices\fR
+Integrates Homebrew formulae with macOS\'s \fBlaunchctl\fR manager: \fIhttps://github\.com/Homebrew/homebrew\-services\fR
+.
+.SH "CUSTOM EXTERNAL COMMANDS"
 Homebrew, like \fBgit\fR(1), supports external commands\. These are executable scripts that reside somewhere in the \fBPATH\fR, named \fBbrew\-\fR\fIcmdname\fR or \fBbrew\-\fR\fIcmdname\fR\fB\.rb\fR, which can be invoked like \fBbrew\fR \fIcmdname\fR\. This allows you to create your own commands without modifying Homebrew\'s internals\.
 .
 .P
@@ -1007,7 +1021,7 @@ http_proxy=http://<user>:<password>@<host>:<port> brew install foo
 Homebrew Documentation: \fIhttps://github\.com/Homebrew/brew/blob/master/docs/\fR
 .
 .P
-\fBgit\fR(1), \fBgit\-log\fR(1)
+\fBbrew\-cask\fR(1), \fBgit\fR(1), \fBgit\-log\fR(1)
 .
 .SH "AUTHORS"
 Homebrew\'s lead maintainer is Mike McQuaid\.