Fix image paths and broken internal links for Endpoint Protector KB reorganization.

Changes:
- Renamed images directory to 0-images
- Updated all 123 image path references to use relative paths
- Fixed 6 broken internal links to reflect new categorized subfolder structure:
  - managing-system-administrators -> administration-security-and-monitoring/
  - how-to-configure-user-remediation-for-device-control -> device-control-and-access-management/
  - enabling-user-remediation-in-content-aware-protection -> content-aware-protection-and-dpi/
  - set-rights-for-a-specific-device -> device-control-and-access-management/
  - enable_two-factor_authentication_for_system_admins -> administration-security-and-monitoring/
  - create_a_system_backup_v2 -> enforced-encryption-and-easylock/
  - how_to_perform_a_backup_restore -> enforced-encryption-and-easylock/

Author: zoeycastillo