Documentation for targets "rebuild" and "retest"

[Aleksey Cheusov <vle%gmx.net@localhost>]

Unless any one object I'll commit the following

Index: doc/guide/files/build.xml
===================================================================
RCS file: /cvsroot/pkgsrc/doc/guide/files/build.xml,v
retrieving revision 1.89
diff -u -r1.89 build.xml
--- doc/guide/files/build.xml	20 Jan 2023 12:21:56 -0000	1.89
+++ doc/guide/files/build.xml	6 May 2024 18:18:13 -0000
@@ -1249,6 +1249,31 @@
 	  information on this target.</para>
 	</listitem>
       </varlistentry>
+
+      <varlistentry>
+	<term>rebuild</term>
+
+	<listitem>
+	  <para>If you did a <command>make build</command> and you
+	  noticed some further modifications of sources are needed,
+	  you can repeat the build with this target, which will ignore
+	  the <quote>already build</quote> flag. This target is
+	  helpful while working of patches.</para>
+	</listitem>
+      </varlistentry>
+
+      <varlistentry>
+	<term>retest</term>
+
+	<listitem>
+	  <para>If you did a <command>make test</command> and you
+	  noticed some further modifications of sources are needed,
+	  you can repeat the test with this target, which will ignore
+	  the <quote>already tested</quote> flag. This target is
+	  helpful while working of patches.</para>
+	</listitem>
+      </varlistentry>
+
     </variablelist>
   </sect1>
 </chapter>