Fix broken GNOME URLs

GNOME has moved from git to GitLab. The default redirection is assuming
projects have a "master" branch, whereas some are using "main", resulting in a
404.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/concepts/application-entry-points.md

@@ -789,7 +789,7 @@ Exec=/usr/Applications/org.apertis.Frampton/bin/frampton-control --shuffle-all
 [Desktop Entry placeholders]: http://standards.freedesktop.org/desktop-entry-spec/latest/ar01s06.html#exec-variables
 [Desktop Menu categories]: http://standards.freedesktop.org/menu-spec/latest/apa.html
 [Frampton multiple entry points]: https://gitlab.apertis.org/appfw/frampton/tree/v0.6.1/scripts
-[GDesktopAppInfo]: https://git.gnome.org/browse/glib/tree/gio/gdesktopappinfo.c#n1997
+[GDesktopAppInfo]: https://gitlab.gnome.org/GNOME/glib/-/blob/main/gio/gdesktopappinfo.c#L2007
 [localestring]: https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#localized-keys
 [PulseAudio media roles]: http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/ApplicationProperties/
 [Reversed domain name]: https://en.wikipedia.org/wiki/Reverse_domain_name_notation

content/concepts/preferences-and-persistence.md

@@ -1845,7 +1845,7 @@ As discussed in the above sections, we recommend:
 
 [D-Bus-secret-service]: http://standards.freedesktop.org/secret-service/
 
-[GSettings-schema]: https://git.gnome.org/browse/glib/tree/gio/gschema.dtd
+[GSettings-schema]: https://gitlab.gnome.org/GNOME/glib/-/blob/main/gio/gschema.dtd
 
 [GVariant type]: https://developer.gnome.org/glib/stable/glib-GVariantType.html#id-1.6.18.6.9
 

content/guides/processes.md

@@ -106,7 +106,7 @@ used by most Linux applications. It gives automatic support for `--help`
 output, and short and long option parsing.
 
 An example of using `GApplication` together with `GOptionContext` is
-[here](https://git.gnome.org/browse/glib/tree/gio/tests/gapplication-example-cmdline3.c).
+[here](https://gitlab.gnome.org/GNOME/glib/-/blob/main/gio/tests/gapplication-example-cmdline3.c).
 
 # External links