feat: add Go, PHP, and Laravel SDKs

- Go SDK: zero deps, functional options pattern, full endpoint coverage
- PHP SDK: PHP 8.1+, curl-based, PdfOptions class, PSR-4 autoloading
- Laravel package: ServiceProvider, Facade, config publishing
- All SDKs document complete PDF options including new v0.4.5 params

sdk/php/README.md

@@ -0,0 +1,156 @@
+# DocFast PHP SDK
+
+Official PHP client for the [DocFast](https://docfast.dev) HTML/Markdown to PDF API.
+
+## Requirements
+
+- PHP 8.1+
+- ext-curl
+- ext-json
+
+## Installation
+
+```bash
+composer require docfast/docfast-php
+```
+
+## Quick Start
+
+```php
+use DocFast\Client;
+
+$client = new Client('df_pro_your_api_key');
+
+// HTML to PDF
+$pdf = $client->html('<h1>Hello World</h1>');
+file_put_contents('output.pdf', $pdf);
+```
+
+## Usage
+
+### HTML to PDF
+
+```php
+$pdf = $client->html('<h1>Hello</h1><p>My document</p>');
+```
+
+### HTML with CSS
+
+```php
+$pdf = $client->html(
+    '<h1>Styled</h1>',
+    'h1 { color: navy; font-family: Georgia; }'
+);
+```
+
+### HTML with PDF Options
+
+```php
+use DocFast\PdfOptions;
+
+$options = new PdfOptions();
+$options->format = 'Letter';
+$options->landscape = true;
+$options->margin = ['top' => '20mm', 'bottom' => '20mm', 'left' => '15mm', 'right' => '15mm'];
+$options->printBackground = true;
+
+$pdf = $client->html('<h1>Report</h1>', null, $options);
+```
+
+### Markdown to PDF
+
+```php
+$pdf = $client->markdown('# Hello World\n\nThis is **bold** text.');
+```
+
+### URL to PDF
+
+```php
+$pdf = $client->url('https://example.com');
+```
+
+### Headers and Footers
+
+```php
+$options = new PdfOptions();
+$options->displayHeaderFooter = true;
+$options->headerTemplate = '<div style="font-size:10px;text-align:center;width:100%">My Document</div>';
+$options->footerTemplate = '<div style="font-size:10px;text-align:center;width:100%">Page <span class="pageNumber"></span>/<span class="totalPages"></span></div>';
+$options->margin = ['top' => '40mm', 'bottom' => '20mm'];
+
+$pdf = $client->html($html, null, $options);
+```
+
+### Custom Page Size
+
+```php
+$options = new PdfOptions();
+$options->width = '8.5in';
+$options->height = '11in';
+$options->scale = 0.8;
+
+$pdf = $client->html($html, null, $options);
+```
+
+### Templates
+
+```php
+// List templates
+$templates = $client->templates();
+
+// Render a template
+$pdf = $client->renderTemplate('invoice', [
+    'company' => 'Acme Corp',
+    'items' => [['name' => 'Widget', 'price' => 9.99]],
+]);
+```
+
+## PDF Options
+
+| Option | Type | Default | Description |
+|--------|------|---------|-------------|
+| `format` | string | `"A4"` | Page size: A4, Letter, Legal, A3, A5, Tabloid |
+| `landscape` | bool | `false` | Landscape orientation |
+| `margin` | array | `null` | Margins with top/bottom/left/right keys (CSS units) |
+| `printBackground` | bool | `true` | Print background graphics |
+| `filename` | string | `null` | Suggested filename |
+| `headerTemplate` | string | `null` | HTML header template |
+| `footerTemplate` | string | `null` | HTML footer template |
+| `displayHeaderFooter` | bool | `false` | Show header/footer |
+| `scale` | float | `1` | Rendering scale (0.1–2.0) |
+| `pageRanges` | string | `null` | Pages to print (e.g. "1-3,5") |
+| `preferCSSPageSize` | bool | `false` | Prefer CSS @page size |
+| `width` | string | `null` | Custom paper width |
+| `height` | string | `null` | Custom paper height |
+
+## Error Handling
+
+```php
+use DocFast\DocFastException;
+
+try {
+    $pdf = $client->html('<h1>Test</h1>');
+} catch (DocFastException $e) {
+    echo "Error: {$e->getMessage()} (status: {$e->statusCode})\n";
+}
+```
+
+## Configuration
+
+```php
+// Custom base URL
+$client = new Client('key', 'https://staging.docfast.dev');
+
+// Custom timeout (seconds)
+$client = new Client('key', 'https://docfast.dev', 120);
+```
+
+## Laravel Integration
+
+See the [DocFast Laravel package](../laravel/) for a dedicated Laravel integration with facades, config, and service provider.
+
+## Links
+
+- [Documentation](https://docfast.dev/docs)
+- [API Reference](https://docfast.dev/openapi.json)
+- [Get an API Key](https://docfast.dev)