[Translation] Fix invalid caution block

Author: alexandre-daubois

translation.rst

@@ -410,9 +410,9 @@ You can also specify the message domain and pass some additional variables:
 
 .. caution::
 
-Using the translation tag has the same effect as the filter, but with one
-major difference: automatic output escaping is **not** applied to translations
-using a tag.
+    Using the translation tag has the same effect as the filter, but with one
+    major difference: automatic output escaping is **not** applied to translations
+    using a tag.
 
 Forcing the Translator Locale
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