Add Pre-Commit hook config docs

README.md

@@ -1,7 +1,7 @@
 # repo-toc
 
 [![npm version](https://badge.fury.io/js/repo-toc.svg)](https://badge.fury.io/js/repo-toc)  
-Easily generate a markdown Table of Contents (TOC) for your GitHub repository.
+Easily generate a markdown Table of Contents (TOC) for your GitHub repository. Automatically respects `.gitignore` files and excludes ignored files and directories from the TOC.
 
 ## Installation
 
@@ -55,13 +55,27 @@ Options:
   -x, --exclude  Directories to exclude (comma-separated)              [string]
   -h, --help     Show help                                             [boolean]
 
-Note: Files and directories in .gitignore are automatically excluded.
+**Important**: Files and directories listed in `.gitignore` files are automatically excluded from the TOC generation. This includes:
+- Files and directories specified in `.gitignore` at any level in your repository
+- Common ignored patterns like `node_modules/`, `dist/`, `build/`, `.git/`, etc.
+- You can still use the `--exclude` option to exclude additional directories beyond what's in `.gitignore`
 ```
 
 ```
 repo-toc
 ```
 
+### .gitignore Support
+
+`repo-toc` automatically respects `.gitignore` files throughout your repository:
+
+- **Automatic exclusion**: Files and directories listed in `.gitignore` are automatically excluded from TOC generation
+- **Multi-level support**: Respects `.gitignore` files at any directory level in your repository
+- **Common patterns**: Automatically excludes common ignored patterns like `node_modules/`, `dist/`, `build/`, `.git/`, etc.
+- **Additional exclusions**: You can still use the `--exclude` option to exclude additional directories beyond what's in `.gitignore`
+
+This ensures your TOC only includes files that are actually tracked in your repository, keeping it clean and relevant.
+
 ### Usage Examples
 
 Generate TOC excluding specific directories:
@@ -74,7 +88,123 @@ Generate TOC for only JavaScript files, excluding test directories:
 repo-toc --ext .js,.ts --exclude tests,__tests__,spec
 ```
 
-**Note**: The tool automatically respects `.gitignore` files and excludes any files or directories listed there, in addition to your manual exclusions.
+**Note**: The tool automatically respects `.gitignore` files and excludes any files or directories listed there, in addition to your manual exclusions. This ensures your TOC only includes files that are actually tracked in your repository.
+
+### Use with Pre-commit Hooks
+
+You can integrate `repo-toc` with pre-commit hooks to automatically generate and update the TOC before each commit. This ensures your TOC is always up-to-date.
+
+#### Setup
+
+1. **Install pre-commit** (if not already installed):
+```bash
+pip install pre-commit
+```
+
+2. **Add repo-toc to your package.json**:
+```json
+{
+  "devDependencies": {
+    "repo-toc": "^1.2.0"
+  },
+  "scripts": {
+    "generate-toc": "./.github/hooks/generate-toc.sh",
+    "install-hooks": "pre-commit install"
+  }
+}
+```
+
+3. **Create a pre-commit hook script** (`.github/hooks/generate-toc.sh`):
+```bash
+#!/bin/bash
+set -e
+
+echo "🔄 Generating Table of Contents..."
+
+# Check if Node.js and npm are available
+if ! command -v node &> /dev/null || ! command -v npm &> /dev/null; then
+    echo "❌ Node.js/npm is not installed. Please install Node.js to generate TOC."
+    exit 1
+fi
+
+# Install repo-toc if not already installed
+if ! npm list -g repo-toc &> /dev/null; then
+    echo "📦 Installing repo-toc globally..."
+    npm install -g repo-toc
+fi
+
+# Generate TOC for README.md
+if [ -f "README.md" ]; then
+    echo "📝 Updating Table of Contents in README.md..."
+
+    # Create a backup
+    cp README.md README.md.backup
+
+    # Generate TOC with repo-toc
+    repo-toc -i README.md
+
+    # Check if the file was modified
+    if ! cmp -s README.md README.md.backup; then
+        echo "✅ Table of Contents updated successfully!"
+        # Add the updated file to git staging area
+        git add README.md
+    else
+        echo "ℹ️  Table of Contents is already up to date."
+    fi
+
+    # Clean up backup
+    rm README.md.backup
+else
+    echo "❌ README.md not found in current directory"
+    exit 1
+fi
+
+echo "🎉 TOC generation completed!"
+```
+
+4. **Configure pre-commit** (`.pre-commit-config.yaml`):
+```yaml
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.4.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-markdown
+        args: [--fix]
+
+  - repo: local
+    hooks:
+      - id: generate-toc
+        name: Generate Table of Contents
+        entry: ./.github/hooks/generate-toc.sh
+        language: script
+        files: '^README\.md$'
+        pass_filenames: false
+        stages: [commit]
+
+  - repo: https://github.com/igorshubovych/markdownlint-cli
+    rev: v0.37.0
+    hooks:
+      - id: markdownlint
+        args: [--fix]
+        files: \.md$
+```
+
+5. **Install the pre-commit hooks**:
+```bash
+npm run install-hooks
+# or
+pre-commit install
+```
+
+#### Benefits
+
+- **Automatic TOC updates**: TOC is generated/updated automatically before each commit
+- **Consistent formatting**: Ensures TOC follows the same format across all commits
+- **No manual intervention**: Developers don't need to remember to update the TOC
+- **Integration with other hooks**: Works seamlessly with markdown linting and other pre-commit hooks
 
 ### Use with Github actions
 It will auto generate the TOC after you commit things on Github. You use this github action
@@ -155,7 +285,9 @@ Generates a Table of Contents for the specified directory.
   - **`filePath`** (string): The path where the generated TOC will be written.  
     - Default: `__dirname + "/README.md"`.
   - **`excludedDirs`** (array of strings): An array of directory names to exclude from the TOC.  
-    - Default: `[]`. Note: Directories starting with `.` and files/directories in `.gitignore` are automatically excluded.
+    - Default: `[]`. 
+    - **Automatic exclusions**: Directories starting with `.` and files/directories listed in `.gitignore` files are automatically excluded, regardless of this parameter.
+    - This parameter allows you to exclude additional directories beyond what's already ignored by `.gitignore`.
 
 **Returns**:  
 `void`