Fixed typo

Author: mnocon

docs/content_management/pages/create_custom_page_block.md

@@ -23,7 +23,7 @@ First, add the following [YAML configuration](configuration.md#configuration-fil
 
 `event` is the internal name for the block, and `name` indicates the name under which the block is available in the interface.
 You also set up the category in the **Page blocks** toolbox that the block appears in.
-In this case, it doesn't show with the rest of the built-in blocks, but in a separate "Custom" category.
+In this case, it doesn't show up with the rest of the built-in blocks, but in a separate "Custom" category.
 The thumbnail for the block can be one of the pre-existing icons, like in the example above, or you can use a custom SVG file.
 
 A block can have multiple attributes that you edit when adding it to a page.