Introduce dynamic language inference for code blocks

The hook now automatically infers the markdown language identifier from the source file extension
instead of hardcoding `php`. This allows proper syntax highlighting for GraphQL, JavaScript,
TypeScript, and many other file types in the README.

Author: ruudk

README.md

@@ -38,7 +38,7 @@ The hook automatically stages the updated README.md if changes are detected, ens
 
 ### Syncing Source Code
 
-To sync a code example with a source file, add a comment before your code block:
+To sync a code example with a source file, add a comment before your code block. The language identifier (e.g., `php`, `graphql`, `javascript`) is automatically inferred from the file extension:
 
 ````markdown
 <!-- source: examples/demo.php -->
@@ -47,6 +47,8 @@ To sync a code example with a source file, add a comment before your code block:
 ```
 ````
 
+The hook supports a wide range of file extensions including `.php`, `.graphql`, `.gql`, `.js`, `.ts`, `.json`, `.yml`, `.yaml`, `.sql`, and many more.
+
 ### Syncing Output (Optional)
 
 To show the output of executing a PHP file, use:

src/SyncReadmeExamples.php

@@ -62,12 +62,13 @@ private function syncReadmeWithExamples(string $readme, string $repositoryRoot,
             // Check for source comment
             if (preg_match('/^<!-- source: (.+) -->$/', trim($line), $matches)) {
                 $sourceFile = $matches[1];
+                $language = $this->getLanguageFromExtension($sourceFile);
                 $result[] = $line; // Keep the source comment
                 ++$i;
 
                 // Process the code block
-                if ($i < count($lines) && preg_match('/^```php\s*$/', $lines[$i])) {
-                    $result[] = $lines[$i]; // Keep ```php
+                if ($i < count($lines) && preg_match('/^```\w*\s*$/', $lines[$i])) {
+                    $result[] = '```' . $language; // Use inferred language
                     ++$i;
 
                     // Skip old code content until closing ```
@@ -262,4 +263,39 @@ private function normalizeOutput(string $output) : string
 
         return implode("\n", $lines);
     }
+
+    /**
+     * Infer the language identifier from file extension
+     */
+    private function getLanguageFromExtension(string $filePath) : string
+    {
+        $extension = pathinfo($filePath, PATHINFO_EXTENSION);
+
+        return match ($extension) {
+            'php' => 'php',
+            'graphql', 'gql' => 'graphql',
+            'js', 'mjs', 'cjs' => 'javascript',
+            'ts', 'mts', 'cts' => 'typescript',
+            'json' => 'json',
+            'yml', 'yaml' => 'yaml',
+            'xml' => 'xml',
+            'sql' => 'sql',
+            'sh', 'bash' => 'bash',
+            'py' => 'python',
+            'rb' => 'ruby',
+            'go' => 'go',
+            'rs' => 'rust',
+            'java' => 'java',
+            'c' => 'c',
+            'cpp', 'cc', 'cxx' => 'cpp',
+            'cs' => 'csharp',
+            'swift' => 'swift',
+            'kt', 'kts' => 'kotlin',
+            'md', 'markdown' => 'markdown',
+            'html', 'htm' => 'html',
+            'css' => 'css',
+            'scss', 'sass' => 'scss',
+            default => '',
+        };
+    }
 }