2025-09-20: Add VSCode integration configuration for NairoVIM

[john-mutuma]

What does this PR do?

This PR adds comprehensive VSCode integration support to NairoVIM, enabling users to use NairoVIM's powerful configuration within VSCode's Neovim extension. The implementation includes a complete VSCode-specific configuration with optimized keymaps, plugin setup, and VSCode action integrations.

• Add complete VSCode configuration structure under nairovim-vscode/
• Configure leader keys (comma as primary, space as local leader)
• Implement system clipboard operations with leader key shortcuts
• Add VSCode-specific action integrations (references, inline chat, window management)
• Set up lazy.nvim plugin management for VSCode environment
• Include essential editing plugins (emmet, surround, autotag, highlighted yank)

Why is it needed?

Many developers use VSCode as their primary editor but want to leverage Neovim's powerful modal editing and customization capabilities. This integration allows NairoVIM users to maintain a consistent editing experience across both standalone Neovim and VSCode environments, while taking advantage of VSCode's built-in features and extensions.

How have the changes been tested?

• Verified that the VSCode configuration loads without errors
• Tested key mappings for system clipboard operations
• Confirmed VSCode action integrations work properly
• Validated lazy.nvim plugin loading in VSCode environment
• Ensured no conflicts with existing NairoVIM configuration

Screenshots (if applicable)

N/A - Configuration changes only

Checklist

• VSCode core configuration implemented
• Key mappings configured for VSCode integration
• Plugin management set up with lazy.nvim
• Essential editing plugins included
• No conflicts with main NairoVIM configuration
• Code follows project conventions and styling
• Commit message follows conventional commit format