ref-manual: Added api-documentation to distro features

Fixes [YOCTO #8584]

Updated the "Distro Features" section to include the
"api-documentation" feature.

(From yocto-docs rev: ad02528f13390c2c0dc5717c1f9088212def37be)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-features.xml

@@ -142,6 +142,14 @@
                 <listitem><para><emphasis>alsa:</emphasis> Include ALSA support
                     (OSS compatibility kernel modules installed if available).
                     </para></listitem>
+                <listitem><para><emphasis>api-documentation:</emphasis>
+                    Enables generation of API documentation during recipe
+                    builds.
+                    The resulting documentation is added to SDK tarballs
+                    when the
+                    <filename>bitbake -c populate_sdk</filename> command
+                    is used.
+                    </para></listitem>
                 <listitem><para><emphasis>bluetooth:</emphasis> Include
                     bluetooth support (integrated BT only).</para></listitem>
                 <listitem><para><emphasis>bluez5:</emphasis> Include

documentation/sdk-manual/sdk-appendix-customizing.xml

@@ -4,12 +4,10 @@
 
 <appendix id='sdk-appendix-customizing'>
 
-<title>Customizing the SDK</title>
+<title>Customizing the Extensible SDK</title>
 
 <para>
-    This appendix presents customizations you can apply to both the standard
-    and extensible SDK.
-    Each subsection identifies the type of SDK to which the section applies.
+    This appendix presents customizations you can apply to the extensible SDK.
 </para>
 
 <section id='sdk-configuring-the-extensible-sdk'>