minor #6370 Fixed typo (tabbi89)

This PR was submitted for the 3.0 branch but it was merged into the 2.3 branch instead (closes #6370).

Discussion
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Fixed typo

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | -

Commits
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c68c61a Fixed typo

Author: xabbuh

cookbook/assetic/php.rst

@@ -40,7 +40,7 @@ Organizing your Web Asset Files
 -------------------------------
 
 This example will include a setup using the Bootstrap CSS framework, jQuery, FontAwesome
-and some regular CSS and and JavaScript application files (called ``main.css`` and
+and some regular CSS and JavaScript application files (called ``main.css`` and
 ``main.js``). The recommended directory structure for this set-up looks like this:
 
 .. code-block:: text