MAGEDOC-3755: Fix configuration docs

Fixes from review

Author: bdenham

docs/reference/configurations.md

@@ -48,7 +48,7 @@ There are a number of child elements which can be configured, these are typicall
 | `parents`           | Defines the default policy and matrix of which content types this content type can have as a parent. For instance the Slide content type defines a default policy of `deny` with an exception allowing this content type to only be housed within the Slider content type. |
 | `children`          | Similar to the `parents` option, however this defines the allowed `children` of the current content type. As with the Slide example this time the Slider defines the Slide as it's only allowed child. |
 | `appearances`       | Configures various appearances along with associated data mapping elements. This is a crucial part of all content types and defines how the master and preview systems should retrieve and display their data. |
-| `is_system`         | Determines menu visibility for the component. System components are visible in the menu. The default value for this is true. By setting this to false, you can hide child or "special" content types that are added by other content types. For examples, the Slide is not able to be dragged onto the stage itself, thus it is not a system content type. |
+| `is_system`         | Determines menu visibility for the content type. System content types are visible in the menu. The default value for this is true. By setting this to false, you can hide child or "special" content types that are added by other content types. For example, you cannot directly drag a Slide content type onto the stage, which means it is not a system content type. |
 | `additional_data`   | Allows you to specify additional data for the component. See [additional configurations](../how-to/how-to-add-additional-configurations.md) for more information. |
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