Major repository cleanup and enhancement

- Reorganize documentation: moved old docs to docs/ directory
- Add comprehensive README.md with build options and usage guide
- Add detailed CONTRIBUTING.md with help content management guide
- Create Makefile for automated building and testing
- Add Dockerfile.scratch for building from Ubuntu 20.04 base
- Enhance all Dockerfiles with PowerShell + PSScriptAnalyzer
- Add modern shells: zsh (with plugins) and fish (with config)
- Add modern CLI tools: fd-find, ripgrep, fzf
- Create comprehensive help system with cheat/TLDR/fish completions
- Add helper scripts for help content management and coverage checking
- Fix Dockerfile.remnux script references
- Support three build variants: upstream (REMnux), scratch (Ubuntu), kali

Build options:
  - make build-upstream: Fast, uses REMnux upstream (recommended)
  - make build-scratch: Full control, builds from Ubuntu 20.04
  - make build-kali: Legacy Kali Linux base

Features:
  - PowerShell with PSScriptAnalyzer module
  - Modern shells (zsh, fish) with custom configurations
  - Enhanced help system (cheat sheets, TLDR pages, fish completions)
  - Help coverage checking and bulk import tools
  - Comprehensive documentation for users and contributors

scripts/add-tool-cheats.sh

@@ -0,0 +1,173 @@
+#!/bin/bash
+# Add cheat sheets for fd-find, ripgrep, zsh, fish
+
+CHEAT_DIR="/opt/cheatsheets/personal"
+mkdir -p "$CHEAT_DIR"
+
+# fd-find cheat sheet
+cat > "$CHEAT_DIR/fd" << 'EOF'
+# fd (fdfind) - Fast and user-friendly alternative to find
+
+# Find files by name
+fdfind pattern
+
+# Find in specific directory
+fdfind pattern /path/to/search
+
+# Find only files (no directories)
+fdfind -t f pattern
+
+# Find only directories
+fdfind -t d pattern
+
+# Case-insensitive search
+fdfind -i PDF
+
+# Include hidden and ignored files
+fdfind -H pattern
+
+# Execute command on results
+fdfind pattern -x rm
+
+# Find and show absolute paths
+fdfind -a pattern
+
+# Find files modified in last 24 hours
+fdfind -t f --changed-within 24h
+
+# Find PDF files in current directory
+fdfind -e pdf
+
+# Exclude directories from search
+fdfind pattern -E node_modules -E vendor
+EOF
+
+# ripgrep cheat sheet
+cat > "$CHEAT_DIR/rg" << 'EOF'
+# ripgrep (rg) - Fast recursive grep alternative
+
+# Basic search
+rg pattern
+
+# Case-insensitive search
+rg -i pattern
+
+# Search specific file types
+rg -t py pattern
+rg -t js pattern
+
+# Search in specific files
+rg pattern -g '*.pdf'
+
+# Show context (3 lines before/after)
+rg -C 3 pattern
+
+# Show only filenames with matches
+rg -l pattern
+
+# Count matches per file
+rg -c pattern
+
+# Search for exact word
+rg -w word
+
+# Search hidden files
+rg --hidden pattern
+
+# Search compressed files
+rg -z pattern file.gz
+
+# Find URLs in files
+rg 'https?://[^\s]+'
+
+# Find suspicious JavaScript in PDFs
+rg -i 'javascript|openaction' -g '*.pdf'
+
+# Search with file types excluded
+rg pattern --type-not python
+
+# Multiline search
+rg -U 'pattern1.*pattern2'
+EOF
+
+# ripgrep alias
+cp "$CHEAT_DIR/rg" "$CHEAT_DIR/ripgrep"
+
+# zsh cheat sheet
+cat > "$CHEAT_DIR/zsh" << 'EOF'
+# zsh - Z Shell with powerful features
+
+# Start zsh
+zsh
+
+# Set zsh as default shell
+chsh -s $(which zsh)
+
+# Autocompletion
+# Type command and press TAB
+
+# History search
+# Type start of command and press UP arrow
+
+# Directory stack
+dirs -v        # Show directory stack
+pushd /path    # Push directory and cd
+popd           # Pop and return to previous
+
+# Glob patterns
+ls **/*.pdf    # Recursive glob
+ls *.pdf~*.bak # Exclude pattern
+
+# Aliases (already configured in container)
+ll             # ls -lah
+fd             # fdfind
+analyse        # fhelp
+?              # fhelp
+
+# History commands
+history        # Show all history
+history 10     # Show last 10
+!$             # Last argument of previous command
+!!             # Repeat last command
+EOF
+
+# fish cheat sheet
+cat > "$CHEAT_DIR/fish" << 'EOF'
+# fish - Friendly Interactive Shell
+
+# Start fish
+fish
+
+# Set fish as default shell  
+chsh -s $(which fish)
+
+# Autocompletion
+# Type command and press TAB (shows suggestions automatically)
+
+# History search
+# Type start of command and see suggestions
+# Press RIGHT arrow to accept
+
+# Command abbreviations
+abbr --add gco git checkout
+abbr --list
+abbr --erase gco
+
+# Functions (instead of aliases)
+function ll
+    ls -lah $argv
+end
+funcsave ll    # Save function permanently
+
+# Environment variables
+set -x PATH /new/path $PATH    # Export
+set -e VARIABLE                # Erase
+
+# Configuration
+fish_config    # Open web-based configuration
+
+# Plugins (fisher)
+# curl -sL https://git.io/fisher | source && fisher install jorgebucaran/fisher
+EOF
+
+echo "✅ Added cheat sheets for fd, ripgrep, zsh, fish"