Document -D option to msi

src/ioc/dbtemplate/msi.html

@@ -24,7 +24,7 @@ accepted by the EPICS IOC's dbLoadTemplate command.</p>
 
 <h2>Command Syntax:</h2>
 
-<pre>msi -V -g -o<i>outfile</i> -I<i>dir</i> -M<i>subs</i> -S<i>subfile</i> <i>template</i></pre>
+<pre>msi -V -g -D -o<i>outfile</i> -I<i>dir</i> -M<i>subs</i> -S<i>subfile</i> <i>template</i></pre>
 
 <p>All parameters are optional. The -o, -I, -M, and -S switches may be
 separated from their associated value string by spaces if desired. Output will
@@ -46,6 +46,13 @@ be written to stdout unless the -o option is given.</p>
     this was the behavior of previous versions of msi, but it does not follow
     common scoping rules and is discouraged.</dd>
 
+  <dt><tt>-D</tt></dt>
+    <dd>Output dependency information suitable for including by a Makefile to
+    stdout instead of performing the macro substitutions. The <tt>-o</tt> option
+    must be given to specify the target name for the dependency rules. Other
+    options should be given exactly as will be used in the macro substitution
+    process.</dd>
+
   <dt><tt>-o</tt> <i>file</i></dt>
     <dd>Output will be written to the specifed file rather than to the standard
     output.</dd>