update void basics

distros/void/void_basics.md

@@ -1,7 +1,21 @@
 ---
 title: "Void Linux Basics"
-tags: [ "Documentation", "distros" ]
+tags: [ "Documentation", "distros", "Void" ]
 ---
+# Updates
+
+Update all packages with
+
+> sudo xbps-install -Su
+
+See [xbps](xbps.md) for more.
+
+# Remove old packages
+
+Void keeps *every* version of everything you install, so you can roll back to them.
+Remove old packages with:
+
+> sudo xbps-remove -O
 
 # vkpurge
 
@@ -17,8 +31,14 @@ Remove all but the latest with:
 
 > vkpurge rm all
 
-
 # Brightness
-/sys/class/backlight/*/brightness
 
+Look in `/sys/class/backlight/*/brightness`.
+You can change this number to change the screen brightness.
+
+For an easy utility, install `brightnessctl`.
+
+> brightnessctl s 10%-
+
+> brightnessctl s 10%+