feature #5835 Updated CssSelector code example to use the new Converter (hiddewie)

This PR was merged into the 2.8 branch.

Discussion
----------

Updated CssSelector code example to use the new Converter

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.8
| Fixed tickets | #5782

Commits
-------

dfb9b16 Used :: for code block
df4fc7e Updated for CssSelectorConverter class name
9392f80 Updated CssSelector code example to use the new Converter

Author: weaverryan

components/css_selector.rst

@@ -47,11 +47,12 @@ The CssSelector Component
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The component's only goal is to convert CSS selectors to their XPath
-equivalents::
+equivalents, using :method:`Symfony\\Component\\CssSelector\\CssSelectorConverter::toXPath`::
 
-    use Symfony\Component\CssSelector\CssSelector;
+    use Symfony\Component\CssSelector\CssSelectorConverter;
 
-    var_dump(CssSelector::toXPath('div.item > h4 > a'));
+    $converter = new CssSelectorConverter();
+    var_dump($converter->toXPath('div.item > h4 > a'));
 
 This gives the following output: