[DBOPS-1274] feat: update rollback schema method by count

[Sonichigo]

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Description

• Please describe your changes:
  This pull request updates the documentation for Harness Database DevOps, focusing on rollback mechanisms and Artifactory integration. Key changes include restructuring and expanding rollback documentation, clarifying Artifactory usage, and improving accessibility through additional keywords and FAQs.

  • Expanded descriptions of rollback methods (by tag and by count) and added step-by-step guides with visual aids.
  • Introduced tabs to separate "Immediate Rollback" and "Delayed Rollback" scenarios for clarity. Included a caution about transactional DDL limitations.
  • Added an FAQ section addressing common questions about rollback tags, compatibility with Liquibase, and verification of rollback success.

• Jira/GitHub Issue numbers (if any): https://harness.atlassian.net/browse/DBOPS-1274

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