For now, mark this tool as internal (#21)

Author: wouterj

README.md

@@ -1,19 +1,24 @@
-# Code block checker
+# Symfony Code Block Checker
 
-Make sure that code blocks have valid syntax and can actually run.
+Makes sure that code blocks have valid syntax and can actually run.
 
 ```terminal
-$ ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev
+$ php ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev
 
 ::error file=cache,line=377::[Invalid syntax] PHP Parse error:  syntax error, unexpected token "}"
 
  [ERROR] Build completed with 1 errors
 
 
-$ ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev --generate-baseline=baseline.json
-$ ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev --baseline=baseline.json
+$ php ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev --generate-baseline=baseline.json
+$ php ./code-block-checker.php verify:docs /path/to/docs cache.rst controller.rst --env=dev --baseline=baseline.json
 
  [OK] Build completed successfully!
 
 ```
 
+This project is considered **an internal tool** and therefore, you
+**shouldn't use this project in your application**. Unlike the rest of the
+Symfony projects, this repository doesn't provide any support and it doesn't
+guarantee backward compatibility either. Any or the entire project can change,
+or even disappear, at any moment without prior notice.