[devhelp] flatpak: add a comment at the top of the *.json manifest

[Sébastien Wilmet <swilmet src gnome org>]

commit ea4861302a914bf3cb2bb3f30dc260691787fd8a
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Sep 21 15:44:10 2018 +0200

    flatpak: add a comment at the top of the *.json manifest

 flatpak/org.gnome.Devhelp.json | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/flatpak/org.gnome.Devhelp.json b/flatpak/org.gnome.Devhelp.json
index 99a4fd02..bfc7cfaa 100644
--- a/flatpak/org.gnome.Devhelp.json
+++ b/flatpak/org.gnome.Devhelp.json
@@ -1,4 +1,8 @@
 {
+    /* The official Flatpak manifest is the *.yml one, not this one.
+     * This one is for gnome-builder, temporarily until gnome-builder supports
+     * the YAML format.
+     */
     "app-id" : "org.gnome.Devhelp",
     "runtime" : "org.gnome.Sdk",
     "runtime-version" : "master",