minor #6652 Finder::path() method matching directories and files (soyuka)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #6652).

Discussion
----------

`Finder::path()` method matching directories and files

For clarity, adds an example where `path()` is used to match a directory or a file.

ref api-platform/core#575 (comment)

Commits
-------

cd28675 Improve `Finder::path` code example about resulting matches

Author: xabbuh

components/finder.rst

@@ -206,7 +206,10 @@ Path
 Restrict files and directories by path with the
 :method:`Symfony\\Component\\Finder\\Finder::path` method::
 
-    $finder->path('some/special/dir');
+    // matches files that contain "data" anywhere in their paths (files or directories)
+    $finder->path('data');
+    // for example this will match data/*.xml and data.xml if they exist
+    $finder->path('data')->name('*.xml');
 
 On all platforms slash (i.e. ``/``) should be used as the directory separator.