Add markdown linting for consistent documentation

[milkshakeuk]

Description:

Add Markdown linting (e.g., using markdownlint) to ensure consistent formatting and quality for Markdown files in the repository.

Benefits:

• Improved readability and maintainability of Markdown documentation.
• Early detection of style issues and common Markdown pitfalls.
• Consistent documentation style across all contributors.

Acceptance Criteria

• Markdown linting is configured (e.g., via .markdownlint.json or equivalent).
• Add git pre-commit hook for markdown linting
• Markdown linting is integrated into the CI workflow.
• Documentation is updated to inform contributors about the new requirement.

Proposed Steps:

1. Add a Markdown linter configuration file (e.g., .markdownlint.json).
2. Integrate Markdown linting into CI (e.g., GitHub Actions).
3. Update CONTRIBUTING.md to document linting requirements (if present) including any supporting tools such as vscode extension etc.

References:

• markdownlint documentation
• Example markdownlint config
• mardownlint cli
• mardownlint cli2