Remove emoji icons from all markdown files

[Copilot]

This PR removes all emoji icons from markdown files throughout the repository to improve accessibility and maintain a professional documentation style.

Changes Made

Removed emoji icons from the following markdown files while preserving document structure and readability:

• README.md: Removed 25+ emojis from section headers and bullet points including 🧠, 📁, 🔒, 🧼, 🔍, 🗃️, 🔐, 🧪, 🚀, 📊, 📈, etc.
• sql_cli_usage_guide.md: Removed 20+ emojis from section headers and subsections

Files Verified (No Changes Needed)

The following markdown files were checked and contained no emoji icons:

• cli/sample_cli_commands.md
• use_cases_and_review.md
• sql/using_sp_GenerateSchemaJSON_and_nl_to_sql.md

Impact

• Improved accessibility for screen readers and text-based browsers
• Maintained professional documentation tone
• Preserved all original content and structure
• Enhanced compatibility across different platforms and rendering engines

All section headers remain clear and descriptive. The documentation maintains its comprehensive coverage of the GenAI SQL Tools Suite functionality while presenting a cleaner, more professional appearance.

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