README: added Void installation guide

Author: NewbieSaibot

README.md

@@ -34,6 +34,7 @@ https://github.com/user-attachments/assets/5c054ac3-90bb-483e-a8f2-5af191805f04
      * [Debian](#debian)
      * [Guix](#guix)
      * [rde](#rde)
+     * [Void](#void)
      * [Other](#other)
   * [Sway Usage](#sway-usage)
   * [Run](#run)
@@ -189,6 +190,12 @@ But we recommend to use [Guix Home](https://guix.gnu.org/manual/devel/en/html_no
 (feature-swaynotificationcenter)
 ```
 
+### Void
+
+```zsh
+sudo xbps-install -S SwayNotificationCenter
+```
+
 ### Other
 
 #### Dependencies