Merge branch 'flatpak-sudo' into 'master'

Flatpak setup: Drop sudo from flatpak commands

Closes #44

See merge request Librem5/developer.puri.sm!59

Apps/GNOME/Flatpak_setup.rst

@@ -6,5 +6,5 @@ Using flatpak
 The `official flatpak documentation <http://docs.flatpak.org/en/latest/>`_ should be used as reference but we will provide some basic steps for installing flatpak on the dev system::
 
    purism@pureos:~$ sudo apt-get install flatpak
-   purism@pureos:~$ sudo flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
-   purism@pureos:~$ sudo flatpak install flathub org.gnome.Platform//3.30
+   purism@pureos:~$ flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+   purism@pureos:~$ flatpak install flathub org.gnome.Platform//3.30