[ADD] Redshift configuration

The Redshift package on Arch doesn't seem to add a service file anywhere
so we have to add one ourselves in our configuration directory.

Geoclue doesn't seem to want to play nice with Redshift right now, so I
used the manual setting to add Paris' coordinates.

redshift/.config/systemd/user/default.target.wants/redshift-gtk.service

@@ -0,0 +1 @@
+/home/ambroisie/.config/systemd/user/redshift-gtk.service

redshift/.config/systemd/user/redshift-gtk.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Redshift display colour temperature adjustment (GUI)
+Documentation=http://jonls.dk/redshift/
+After=display-manager.service
+
+[Service]
+ExecStart=@bindir@/redshift-gtk
+Restart=always
+
+[Install]
+WantedBy=default.target

redshift/.config/systemd/user/redshift.service

@@ -0,0 +1,12 @@
+[unit]
+description=redshift display colour temperature adjustment
+documentation=http://jonls.dk/redshift/
+after=display-manager.service
+
+[service]
+environment=display=:0
+execstart=/usr/bin/redshift
+restart=always
+
+[install]
+wantedby=default.target