Update README.rst

This fix a typo according to https://github.com/symfony/flex/blob/fabf04baa532b8068558d1e54a9358ef26814449/src/Flex.php#L404, though it doesn't work currently, see symfony/demo#842

Author: yceruto

README.rst

@@ -209,8 +209,8 @@ Don't remove or modify these separators.
     Use ``%generate(secret)%`` as the value of any environment variable to
     replace it with a cryptographically secure random value of 16 bytes.
 
-``composer-scripts`` Configurator
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+``auto-scripts`` Configurator
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 Registers scripts in the ``auto-scripts`` section of the ``composer.json`` file
 to execute them automatically when running ``composer install`` and ``composer
@@ -222,7 +222,7 @@ script (``php-script`` for PHP scripts, ``script`` for any shell script and
 .. code-block:: json
 
     {
-        "composer-scripts": {
+        "auto-scripts": {
             "vendor/bin/security-checker security:check": "php-script",
             "make cache-warmup": "script",
             "assets:install --symlink --relative %PUBLIC_DIR%": "symfony-cmd"