Use anonymous references to fix build warnings

See sphinx-doc/sphinx#3921 (comment)

docs/available-runtimes.rst

@@ -21,8 +21,8 @@ application and contains a set of essential libraries and services, including
 D-Bus, GLib, Gtk3, PulseAudio, X11 and Wayland.
 
 The Freedesktop runtime is maintained `here
-<https://gitlab.com/freedesktop-sdk/freedesktop-sdk/>`_ and has a website
-`here <https://freedesktop-sdk.io/>`_.
+<https://gitlab.com/freedesktop-sdk/freedesktop-sdk/>`__ and has a website
+`here <https://freedesktop-sdk.io/>`__.
 
 Available Freedesktop runtimes:
 
@@ -64,7 +64,7 @@ including:
 * WebKitGTK
 
 The GNOME runtime is maintained `here
-<https://gitlab.gnome.org/GNOME/gnome-build-meta>`_.
+<https://gitlab.gnome.org/GNOME/gnome-build-meta>`__.
 
 Available GNOME runtimes:
 
@@ -87,7 +87,7 @@ Frameworks. It is appropriate for any application that makes use of the KDE
 platform and most Qt-based applications.
 
 The KDE runtime is maintained `here
-<https://invent.kde.org/kde/flatpak-kde-runtime>`_.
+<https://invent.kde.org/kde/flatpak-kde-runtime>`__.
 
 Available KDE runtimes:
 

docs/qt.rst

@@ -42,5 +42,5 @@ straight-forward.
 Contents
 --------
 
-The ``org.kde.Platform`` runtime includes all of Qt, including some KDE Frameworks. If you discover any issues we encourage you to `report them <https://invent.kde.org/kde/flatpak-kde-runtime>`_. If you want more control, it's also possible to use the ``org.freedesktop.Platform`` as a base and bundle the parts of Qt you need.
+The ``org.kde.Platform`` runtime includes all of Qt, including some KDE Frameworks. If you discover any issues we encourage you to `report them <https://invent.kde.org/kde/flatpak-kde-runtime>`__. If you want more control, it's also possible to use the ``org.freedesktop.Platform`` as a base and bundle the parts of Qt you need.