fixed passive voice (#6092)

* Fixed grammar errors

* fixed passive voice in decal doc

* Update Decal.md

* Update Decal.md

* Update Decal.md

Author: emilybrown1

com.unity.render-pipelines.high-definition/Documentation~/Decal.md

@@ -36,9 +36,13 @@ After you enable Decal Layers, you can then use them to decouple Meshes from cer
 
 By default, in the UI for Decal Projectors, Mesh Renderers, or Terrain, Decal Layers are named **Decal Layer 1-7**. To more easily differentiate between them, you can give each Decal Layer a specific name. To do this, open the [HDRP Global Settings](Default-Settings-Window.md), and go to **Decal Layer Names**. Here you can set the name of each Decal Layer individually.
 
-### Performance implications
+### How Decal Layers affect performance
 
-Enabling Decal Layers increases memory usage, has a GPU performance cost and generates more Shader Variants. This increases build time.
+When you enable Decal Layers, it increases the build time of your project. This is because Decal Layers:
+
+* Uses a high amount of memory.
+* Increases GPU performance cost.
+* Generates more [Shader Variants](https://docs.unity3d.com/Manual/shader-variants.html).
 
 If you use the Decal Layer system to disable a decal, via the **Rendering Layer Mask** of a Mesh Renderer or Terrain, it doesn't save on any performance. Instead, to save performance, you need to disable the **Receive Decals** property for the Mesh Renderer or Terrain's Material.