AST-146807: Create Cloud MD file for ast-cli-java-wrapper repository

- Added comprehensive Cloud.md with all essential sections:
  - Project Overview
  - Architecture and design patterns
  - Repository structure
  - Technology stack (Maven, Java 8, Jackson, Lombok, etc.)
  - Development setup and prerequisites
  - Coding standards and guidelines
  - Project rules and conventions
  - Testing strategy with JUnit 5 and code coverage
  - Known issues and limitations

- Included recommended sections:
  - Database schema (N/A for client library)
  - External integrations (AST Platform, Maven Central)
  - Deployment information
  - Performance considerations
  - API/Endpoints/Interfaces documentation
  - Security & Access controls
  - Logging configuration
  - Debugging steps and common issues

- Documentation follows the standardization template from epic AST-146793

Author: cx-aniket-shinde