[gnome-devel-docs] demos: Mention to save the .desktop.in to fit with autogen.sh.

[David King <davidk src gnome org>]

commit 5b58c262210f41b96c85555de08e173a09cdc8f7
Author: Sebastian Rasmussen <sebras gmail com>
Date:   Sat Feb 2 03:46:31 2019 +0100

    demos: Mention to save the .desktop.in to fit with autogen.sh.

 platform-demos/C/hello-world.js.page | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/platform-demos/C/hello-world.js.page b/platform-demos/C/hello-world.js.page
index ec85e4e0..65c22188 100644
--- a/platform-demos/C/hello-world.js.page
+++ b/platform-demos/C/hello-world.js.page
@@ -137,7 +137,7 @@ app.application.run(ARGV);]]></code>
     <p>The example shows you the minimum requirements for a <code>.desktop.in</code> file.</p>
     <code mime="text/desktop" style="numbered"><xi:include href="samples/hello-in-js/hello-world.desktop.in" 
parse="text"><xi:fallback/></xi:include></code>
 
-    <p>Now let's go through some parts of the <code>.desktop.in</code> file.</p>
+    <p>Save this as <file>hello-world.desktop.in</file>. Now let's go through some parts of the 
<code>.desktop.in</code> file.</p>
     <terms>
       <item><title>Name</title><p>The application name.</p></item>
       <item><title>Comment</title><p>A short description of the application.</p></item>