Add documentation for accent-insensitive search feature

- Add comprehensive ACCENT_INSENSITIVE_SEARCH.md documentation
- Remove temporary test file
- Includes usage examples, configuration, and performance considerations

Author: slowestwind

ACCENT_INSENSITIVE_SEARCH.md

@@ -0,0 +1,127 @@
+# Accent-Insensitive Search
+
+This feature allows DataTables to perform accent-insensitive searches, which is particularly useful for Portuguese and other languages that use accented characters.
+
+## Problem
+
+Users often don't type accents when searching but expect to find results with accented characters. For example:
+- Searching for "simoes" should find "Simões"
+- Searching for "joao" should find "João"
+- Searching for "sao paulo" should find "São Paulo"
+
+## Configuration
+
+To enable accent-insensitive search, update your `config/datatables.php` file:
+
+```php
+return [
+    'search' => [
+        'ignore_accents' => true, // Enable accent-insensitive search
+        // ... other search options
+    ],
+    // ... other configurations
+];
+```
+
+## Supported Characters
+
+This feature currently supports Portuguese Brazilian accents:
+
+| Accented Characters | Base Character |
+|-------------------|----------------|
+| Ã/ã/Á/á/À/à/Â/â   | a              |
+| É/é/Ê/ê           | e              |
+| Í/í               | i              |
+| Ó/ó/Ô/ô/Õ/õ       | o              |
+| Ú/ú               | u              |
+| Ç/ç               | c              |
+
+## How It Works
+
+When `ignore_accents` is enabled:
+
+1. **For Collection DataTables**: Both the search term and the data values are normalized to remove accents before comparison
+2. **For Query/Eloquent DataTables**: Database-specific functions are used to normalize characters in SQL queries
+
+### Database Support
+
+- **MySQL**: Uses cascaded `REPLACE()` functions
+- **PostgreSQL**: Uses `UNACCENT()` extension if available, falls back to `REPLACE()`
+- **SQLite**: Uses cascaded `REPLACE()` functions  
+- **SQL Server**: Uses cascaded `REPLACE()` functions
+
+## Examples
+
+### Basic Usage
+
+```php
+use DataTables;
+
+public function getUsersData()
+{
+    return DataTables::of(User::query())
+        ->make(true);
+}
+```
+
+With `ignore_accents => true` in config:
+- Searching "simoes" will match "Simões"
+- Searching "jose" will match "José" 
+- Searching "coracao" will match "Coração"
+
+### Collection Example
+
+```php
+$users = collect([
+    ['name' => 'João Silva'],
+    ['name' => 'María González'], 
+    ['name' => 'José Santos']
+]);
+
+return DataTables::of($users)->make(true);
+```
+
+With accent-insensitive search enabled:
+- Searching "joao" will find "João Silva"
+- Searching "jose" will find "José Santos"
+
+## Performance Considerations
+
+- **Collection DataTables**: Minimal impact as normalization is done in PHP
+- **Query DataTables**: May have slight performance impact due to database function calls
+- Consider adding database indexes on frequently searched columns
+- The feature can be toggled per DataTable instance if needed
+
+## Extending Support
+
+To add support for other languages/accents, modify the `Helper::normalizeAccents()` method in `src/Utilities/Helper.php`:
+
+```php
+public static function normalizeAccents(string $value): string
+{
+    $map = [
+        // Portuguese
+        'Ã' => 'a', 'ã' => 'a', 'Á' => 'a', 'á' => 'a',
+        // Add more mappings for other languages
+        'Ñ' => 'n', 'ñ' => 'n', // Spanish
+        'Ü' => 'u', 'ü' => 'u', // German
+        // ... more mappings
+    ];
+    return strtr($value, $map);
+}
+```
+
+## Testing
+
+The feature includes comprehensive unit tests. To run them:
+
+```bash
+./vendor/bin/phpunit tests/Unit/HelperTest.php --filter test_normalize_accents
+```
+
+## Backward Compatibility
+
+This feature is fully backward compatible:
+- Default configuration has `ignore_accents => false`
+- Existing applications continue to work unchanged
+- No breaking changes to existing APIs