feat: add author metadata to zebbern security skills (#8)

Added metadata block with author: zebbern and version: 1.1 to all 29 security skills originally from claude-code-guide repository:
- active-directory-attacks, api-fuzzing-bug-bounty, aws-penetration-testing
- broken-authentication, burp-suite-testing, cloud-penetration-testing
- ethical-hacking-methodology, file-path-traversal, html-injection-testing
- idor-testing, linux-privilege-escalation, linux-shell-scripting
- metasploit-framework, network-101, pentest-checklist, pentest-commands
- privilege-escalation-methods, red-team-tools, scanning-tools
- shodan-reconnaissance, smtp-penetration-testing, sql-injection-testing
- sqlmap-database-pentesting, ssh-penetration-testing, top-web-vulnerabilities
- windows-privilege-escalation, wireshark-analysis, wordpress-penetration-testing
- xss-html-injection

skills/linux-privilege-escalation/SKILL.md

@@ -1,6 +1,9 @@
 ---
 name: Linux Privilege Escalation
 description: This skill should be used when the user asks to "escalate privileges on Linux", "find privesc vectors on Linux systems", "exploit sudo misconfigurations", "abuse SUID binaries", "exploit cron jobs for root access", "enumerate Linux systems for privilege escalation", or "gain root access from low-privilege shell". It provides comprehensive techniques for identifying and exploiting privilege escalation paths on Linux systems.
+metadata:
+  author: zebbern
+  version: "1.1"
 ---
 
 # Linux Privilege Escalation