[gnome-builder] docs: update various help links

[Christian Hergert <chergert src gnome org>]

commit c2a7dc852de4f9ca9ba97a8f1ce1de097e9310fa
Author: Christian Hergert <chergert redhat com>
Date:   Thu Feb 27 11:51:13 2020 -0800

    docs: update various help links
    
    Fixes #1153

 doc/help/installation.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/doc/help/installation.rst b/doc/help/installation.rst
index 3f4081f23..73c8ac6e6 100644
--- a/doc/help/installation.rst
+++ b/doc/help/installation.rst
@@ -1,13 +1,13 @@
 
 .. _Installation:
 .. _Flatpak: https://flatpak.org
-.. _Stable: https://git.gnome.org/browse/gnome-apps-nightly/plain/gnome-builder.flatpakref?h=stable
-.. _Nightly: https://git.gnome.org/browse/gnome-apps-nightly/plain/gnome-builder.flatpakref
+.. _Stable: https://flathub.org/repo/appstream/org.gnome.Builder.flatpakref
+.. _Nightly: https://nightly.gnome.org/repo/appstream/org.gnome.Builder.flatpakref
 .. _Software: https://wiki.gnome.org/Apps/Software
 .. _GNOME: https://gnome.org/
 .. _JHBuild: https://wiki.gnome.org/Newcomers/BuildGnome
 .. _`Newcomers Tutorial`: https://wiki.gnome.org/Newcomers
-.. _`filing a bug`: https://bugzilla.gnome.org/enter_bug.cgi?product=gnome-builder
+.. _`filing a bug`: https://gitlab.gnome.org/GNOME/gnome-builder/issues
 
 ############
 Installation