[WIP] Fix markdown lint issues and inconsistencies

[Copilot]

Markdown Sanitizer Workflow

Fix markdown lint issues and inconsistencies across all markdown files in the repository.

Plan

• Explore repository and understand markdown files structure
• Identify markdown lint issues using markdownlint-cli
• Create .markdownlint.json configuration file with appropriate rules
• Create automated markdown sanitization workflow
• Run sanitizer on all repository markdown files
• Verify fixes and ensure no regressions
• Document the markdown linting process in contributing guide

Original prompt

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This section details on the original issue you should resolve

<issue_title>[Workflow] Markdown sanitizer</issue_title>
<issue_description>### Workflow Name

Markdown sanitizer

Workflow Description

Go through all markdown files in this repo and fix markdown lint issues and inconsistencies.

Additional Context (Optional)

No response</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Workflow] Markdown sanitizer #6991

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