toaster-manual: Explain the local release

The fact that the Local Yocto Project release does not provide any
compatible layers confuses people. Add a section about the local release
to explain what it does.

[YOCTO #9229]

(From yocto-docs rev: cc7ebcd5a66ff3041a7fdd17e697dfb60b08cadd)

Signed-off-by: Belen <belen@icarus.isw.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/toaster-manual/toaster-manual-setup-and-use.xml

@@ -558,6 +558,70 @@
           </para>
       </section>
 
+      <section id='a-note-on-the-local-yocto-project-release'>
+          <title>A Note on the Local Yocto Project Release</title>
+
+          <para>
+              This note only applies if you have set up Toaster
+              for local development, as explained in
+              <link linkend='starting-toaster-for-local-development'>
+                section 3.1.</link>
+          </para>
+          <para>
+              When you create a project in Toaster, you will be asked to
+              provide a name and to select a Yocto Project release. One
+              of the release options you will find is called
+              <emphasis>Local Yocto Project</emphasis>.
+              <imagedata fileref="figures/new-project.png" align="center" width="9in" />
+          </para>
+
+          <para>
+              When you select the <emphasis>Local Yocto Project</emphasis>
+              release, Toaster will run your builds using the local Yocto
+              Project clone you have in your computer: the same clone
+              you are using to run Toaster. Unless you manually update
+              this clone, your builds will always use the same Git revision.
+          </para>
+
+          <para>
+              If you select any of the other release options, Toaster
+              will fetch the tip of your selected release from the upstream
+              <ulink url='https://git.yoctoproject.org'>Yocto Project
+              repository</ulink> every time you run a build. This effectively
+              means that if your selected release is updated upstream, the
+              Git revision you are using for your builds will change.
+              If you are doing development locally, you might not want this
+              to happen. In that case, the <emphasis>Local Yocto Project</emphasis>
+              release might be the right choice.
+          </para>
+
+          <para>
+              However, the <emphasis>Local Yocto Project</emphasis> release
+              will not provide you with any compatible layers, other than the
+              three core layers that come with the Yocto Project:
+              <itemizedlist>
+                  <listitem><para>
+                      <ulink url='http://layers.openembedded.org/layerindex/branch/master/layer/openembedded-core/'>openembedded-core</ulink>
+                  </para></listitem>
+                  <listitem><para>
+                      <ulink url='http://layers.openembedded.org/layerindex/branch/master/layer/meta-poky/'>meta-poky</ulink>
+                  </para></listitem>
+                  <listitem><para>
+                      <ulink url='http://layers.openembedded.org/layerindex/branch/master/layer/meta-yocto-bsp/'>meta-yocto-bsp</ulink>
+                  </para></listitem>
+              </itemizedlist>
+              <imagedata fileref="figures/compatible-layers.png" align="center" width="9in" />
+          </para>
+
+          <para>
+              If you want to build any other layers, you will need to
+              manually import them into your Toaster project, using the
+              <emphasis>Import layer</emphasis> page.
+              <imagedata fileref="figures/import-layer.png" align="center" width="9in" />
+          </para>
+
+      </section>
+
       <section id='toaster-web-interface-preferred-version'>
           <title>Building a Specific Recipe Given Multiple Versions</title>