Add note about PHP Handlebars

Author: theodorejb

README.md

@@ -5,6 +5,10 @@ Parse [Handlebars](https://handlebarsjs.com) templates to a spec-compliant AST w
 Implements the same lexical analysis and grammar specification as Handlebars.js, so any template
 which can (or cannot) be parsed by Handlebars.js should parse (or error) the same way here.
 
+> [!NOTE]
+> This project is only a parser. To compile Handlebars templates to native PHP for execution,
+> see [PHP Handlebars](https://github.com/devtheorem/php-handlebars), which uses this parser.
+
 ## Installation
 
 `composer require devtheorem/php-handlebars-parser`