dev-manual: Added new section on conserving disk space

For conserving disk space during builds, I added a new section
that tells how to add "rm_work" to your local.conf file.
This information was part of the original YP Quick Start
and was not carried forward into the new brief build
document.

(From yocto-docs rev: 719d70587d908390a134559472d57ce7fced6aae)

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

documentation/dev-manual/dev-manual-common-tasks.xml

@@ -7670,6 +7670,25 @@ Some notes from Cal:
         </para>
     </section>
 
+    <section id='dev-saving-memory-during-a-build'>
+        <title>Conserving Disk Space During Builds</title>
+
+        <para>
+            To help conserve disk space during builds, you can add the
+            following statement to your project's
+            <filename>local.conf</filename> configuration file found in the
+            <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>:
+            <literallayout class='monospaced'>
+     INHERIT += "rm_work"
+            </literallayout>
+            Adding this statement deletes the work directory used for building
+            a recipe once the recipe is built.
+            For more information on "rm_work", see the
+            <ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-rm-work'><filename>rm_work</filename></ulink>
+            class in the Yocto Project Reference Manual.
+        </para>
+    </section>
+
     <section id='building-a-tiny-system'>
         <title>Building a Tiny System</title>