Fix image paths and broken internal links for Directory Manager KB reorganization.

Changes:
- Renamed images directory to 0-images
- Updated all 484 image path references to use relative paths
- Fixed 6 broken internal links to reflect new categorized subfolder structure:
  - walkthrough-search-policy -> security-permissions-and-access-control/
  - enforce-users-to-create-groups -> security-permissions-and-access-control/
  - import-members-to-a-group -> workflows-automation-and-lifecycle-management/
  - add-message-approvers -> configuration-and-integration/
  - best-practices-for-preventing -> security-permissions-and-access-control/
  - best-practices-for-controlling-changes -> reporting-export-and-data-management/
  - trigger-workflow -> workflows-automation-and-lifecycle-management/

Author: zoeycastillo