Add initial LaTeX document for server hardening tutorial

- Created main.tex with document structure and title page
- Added step_01.tex detailing server hardening steps for Ubuntu 24.04
- Included table of contents and sections for SSH setup, system updates, and security measures
- Introduced code listings for commands and configurations
- Generated main.pdf, main.out, main.toc, and main.synctex.gz files

LateX/main.toc

@@ -0,0 +1,10 @@
+\babel@toc {ngerman}{}\relax 
+\contentsline {section}{\numberline {1}Server-Absicherung (Ubuntu 24.04 auf Contabo VPS)}{3}{section.1}%
+\contentsline {subsection}{\numberline {1.1}Schritt 1: SSH-Verbindung testen}{3}{subsection.1.1}%
+\contentsline {subsection}{\numberline {1.2}Schritt 2: System-Updates}{4}{subsection.1.2}%
+\contentsline {subsection}{\numberline {1.3}Schritt 3: SSH-Key-Authentifizierung}{4}{subsection.1.3}%
+\contentsline {subsection}{\numberline {1.4}Schritt 4: SSH-Client-Konfiguration (Alias)}{5}{subsection.1.4}%
+\contentsline {subsection}{\numberline {1.5}Schritt 5: SSH-Timeout auf 20 Minuten}{6}{subsection.1.5}%
+\contentsline {subsection}{\numberline {1.6}Schritt 6: Fail2Ban (Bruteforce-Schutz)}{6}{subsection.1.6}%
+\contentsline {subsection}{\numberline {1.7}Zusammenfassung}{7}{subsection.1.7}%
+\providecommand \tocbasic@end@toc@file {}\tocbasic@end@toc@file