feat(redshift): add redshift for color temperature.

bspwm/bspwmrc

@@ -40,6 +40,15 @@ xautolock -time 10 -locker 'lock' -corners ---- -cornersize 30 &
 hsetroot -fill $WALLPAPER_PATH
 # battery checker
 sh $HOME/.local/bin/check-battery.sh &
+# start redshift
+if pgrep -x redshift > /dev/null
+then
+    pid=$(pidof redshift)
+    kill $pid
+    # we need to wait redshift shutdown, otherwise color temperature is wrong.
+    while kill -0 $pid 2>/dev/null; do sleep 0.01; done
+fi
+redshift &
 
 # ##############################################################################
 # #                                 WINDOW RULES                               #

redshift/redshift.conf

@@ -0,0 +1,51 @@
+[redshift]
+; Daytime temperature
+temp-day=5800
+
+; Night temperature
+temp-night=5000
+
+; Disable or enable fading between color temperatures when Redshift starts or stops
+fade=0
+
+; Set the screen brightness. Default is 1.0.
+brightness=1.0
+
+; Screen brightness at daytime
+brightness-day=0.9
+
+; Screen brightness at night
+brightness-night=0.7
+
+; Gamma adjustment to apply (day and night)
+gamma=0.9
+
+; Set the location-provider: 'geoclue2', 'manual'
+; type 'redshift -l list' to see possible values.
+; The location provider settings are in a different section.
+location-provider=manual
+
+; Set the adjustment-method: 'randr', 'vidmode'
+; type 'redshift -m list' to see all possible values.
+; 'randr' is the preferred method, 'vidmode' is an older API.
+; but works in some cases when 'randr' does not.
+; The adjustment method settings are in a different section.
+adjustment-method=randr
+
+; Configuration of the location-provider:
+; type 'redshift -l PROVIDER:help' to see the settings.
+; ex: 'redshift -l manual:help'
+; Keep in mind that longitudes west of Greenwich (e.g. the Americas)
+; are negative numbers.
+[manual]
+lat=35.0116
+lon=135.7681
+
+; Configuration of the adjustment-method
+; type 'redshift -m METHOD:help' to see the settings.
+; ex: 'redshift -m randr:help'
+; In this example, randr is configured to adjust only screen 0.
+; Note that the numbering starts from 0, so this is actually the first screen.
+; If this option is not specified, Redshift will try to adjust _all_ screens.
+[randr]
+screen=0