minor symfony#21082 [Console] fix typo (GrinWay)

This PR was merged into the 7.3 branch.

Discussion
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[Console] fix typo

Just a little fix. $ sign before the variable

Commits
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432f468 Update tree.rst

Author: javiereguiluz

components/console/helpers/tree.rst

@@ -115,7 +115,7 @@ class and adding nodes to it::
     $testsNode = new TreeNode('tests/');
     $functionalTestsNode = new TreeNode('Functional/');
     $testsNode->addChild($functionalTestsNode);
-    $root->addChild(testsNode);
+    $root->addChild($testsNode);
 
     $tree = TreeHelper::createTree($io, $root);
     $tree->render();