Fixing missing space in configuration docs

Author: SkaveRat

configuration.rst

@@ -69,7 +69,7 @@ readable. These are the main advantages and disadvantages of each format:
 
 * **YAML**: simple, clean and readable, but not all IDEs support autocompletion
   and validation for it. :doc:`Learn the YAML syntax </components/yaml/yaml_format>`;
-* **XML**:autocompleted/validated by most IDEs and is parsed natively by PHP,
+* **XML**: autocompleted/validated by most IDEs and is parsed natively by PHP,
   but sometimes it generates configuration considered too verbose. `Learn the XML syntax`_;
 * **PHP**: very powerful and it allows you to create dynamic configuration, but the
   resulting configuration is less readable than the other formats.