Refactor navigation and add sidebar to notes

- Updated mobile navigation links in _data/navigation.yml for better accessibility.
- Added sidebar configuration to multiple notes under IT-School and HomeServer categories for consistent navigation.
- Ensured all relevant pages now include the mobile_nav sidebar for improved user experience.
- Adjusted sidebar settings in aboutme.md, homeserver_hub.md, index.md, notes.md, and sysengine.md for uniformity.

_pages/index.md

@@ -4,6 +4,8 @@ layout: home
 classes: wide
 author_profile: true
 permalink: /
+sidebar:
+  nav: mobile_nav 
 ---
 
 ## Добро пожаловать в мой цифровой садик! 🌱