Add sidebar navigation, search, page progress tracking, and project structure improvements

[Copilot]

Project-wide review and revamp based on Data-Science-Analytical-Handbook patterns. Adds structured navigation, search, page progress tracking, and improved content organization.

Navigation & Structure

• _data/navigation.yml - Hierarchical sidebar navigation with icons
• _includes/sidebar.html - Collapsible TOC component
• _includes/analytics.html - Google Analytics (G-LHTGZTRTCX)

Layout (_layouts/default.html)

• Sidebar auto-hidden on homepage, visible on content pages
• Client-side search with autocomplete
• "Mark as Complete" progress tracking (localStorage)
• Breadcrumb navigation for docs/recipes
• Active nav state highlighting

CSS Additions

• Sidebar toggle/collapse
• Search dropdown results
• Page progress component
• Breadcrumb styling
• Dark mode for new components
• Mobile responsive breakpoints

README

• Added GitHub Pages link
• Repository content tables
• "How to Use This Material" section
• Fixed corrupted emojis

Content Metadata

Added estimated_time and difficulty front matter:

---
title: Getting Started with Delta Lake and Apache Iceberg
estimated_time: 30 min
difficulty: Beginner
---

Displays in page progress component when present.

Original prompt

revivew the implementatoin, style, and poject style of the following repor: https://github.com/moshesham/Data-Science-Analytical-Handbook

and use it a a guide to do a detailed project wide review of the content, layout, style, messaging, and revamp and imprive the projct

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