code_intentions.md: mention skipBeforeAfter

Author: YannCebron

topics/tutorials/code_intentions.md

@@ -74,6 +74,7 @@ By default, the intention description directory name is the same as the intentio
 It can be customized with the `<descriptionDirectoryName>` element in `<intentionAction>` in <path>plugin.xml</path>.
 
 "Before" and "after" filenames pattern is <path>before.\$LANG_FILE_EXTENSION\$.template</path> and <path>after.\$LANG_FILE_EXTENSION\$.template</path> respectively.
+If before/after preview is not needed, specify `<skipBeforeAfter>true</skipBeforeAfter>` in the `<intentionAction>` in <path>plugin.xml</path>.
 
 > If a plugin project is multi-module, and it combines resources into a single JAR, make sure that all intention description files have unique names or paths.
 > Otherwise, only the last packed description file will exist in the distribution package.