Update _Sidebar.md

Author: gustavo-iniguez-goya

wiki/_Sidebar.md

@@ -3,8 +3,9 @@
 3. [Getting started](Getting-started)
    1. [Events window](The-Events-window)
       1. [Themes](Events-window-themes)
-   3. [Process monitor dialog](Process-monitor-dialog)
-   4. [Pop-up dialogs](Pop-ups-dialogs)
+   2. [Preferences window](The-Preferences-window)
+   3. [Pop-up dialogs](Pop-ups-dialogs)
+   4. [Process monitor dialog](Process-monitor-dialog)
 4. [Configuration](Configurations)
    1. [Monitor method: audit](monitor-method-auditd)
    2. [Monitor method: eBPF](monitor-method-ebpf)