[gegl] docs: add link to commandline documention

[Øyvind Kolås <ok src gnome org>]

commit 4510b930a1e99bf0434f5ce9ac26d6a409af38b8
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Apr 21 14:25:40 2017 +0200

    docs: add link to commandline documention

 docs/index.txt.in |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/docs/index.txt.in b/docs/index.txt.in
index 8ee94cd..712d08c 100644
--- a/docs/index.txt.in
+++ b/docs/index.txt.in
@@ -26,8 +26,8 @@ link:features.html[GEGL Feature list]::
   The "feature list", a technical specification of what GEGL can do.
 link:glossary.html[GEGL glossary]::
   A cheat sheet of terms used in GEGL.
-link:hello-world.html[hello world]::
-  A small C example program source showing how the native C GEGL API can be used.
+link:commandline.html[Commandline reference]::
+  Documentation for using GEGL from the commandline with the gegl binary.
 
 link:api.html[public API reference]::
   The public graph construction and manipulation API for doing image