Removing yarn

Page: https://symfony.com/doc/5.4/frontend/encore/advanced-config.html

This is just to check if you really want to drop yarn, as discussed in symfony/ux#1200

If you merge it, I will remove all other occurrences :-)

Author: ThomasLandauer

frontend/encore/advanced-config.rst

@@ -105,10 +105,6 @@ prefer to build configs separately, pass the ``--config-name`` option:
 
 .. code-block:: terminal
 
-    # if you use the Yarn package manager
-    $ yarn encore dev --config-name firstConfig
-
-    # if you use the npm package manager
     $ npm run dev -- --config-name firstConfig
 
 Next, define the output directories of each build: