Update docs.md with more clear node_color info (#4120)

## What are you changing in this pull request and why?
This mostly updates the documentation of `doc` to better integrate
`node_color` into the page.

## Checklist
- [x] Review the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
and [About
versioning](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
so my content adheres to these guidelines.

website/docs/reference/resource-configs/docs.md

@@ -28,6 +28,7 @@ models:
   - name: model_name
     docs:
       show: true | false
+      node_color: "black"
 
 ```
 
@@ -113,13 +114,13 @@ macros:
 ```
 
 </File>
-
+Also refer to [macro properties](/reference/macro-properties).
 </TabItem>
 
 </Tabs>
 
 ## Definition
-The docs field can be used to provide documentation-specific configuration to models. The only currently supported docs attribute is shown, which controls whether or not models are shown in the auto-generated documentation website.
+The docs field can be used to provide documentation-specific configuration to models. It supports the doc attribute `show`, which controls whether or not models are shown in the auto-generated documentation website. It also supports `node_color` for some node types.
 
 **Note:** hidden models will still appear in the dbt DAG visualization but will be identified as "hidden.”
 
@@ -167,7 +168,7 @@ models:
 
 ## Custom node colors
 
-The `docs` attribute now supports `node_color` to customize the node color in the DAG within dbt docs. You can define node colors in the files below and apply overrides where needed.
+The `docs` attribute now supports `node_color` to customize the display color of some node types in the DAG within dbt docs. You can define node colors in the files below and apply overrides where needed.
 
 `node_color` hiearchy:
 
@@ -176,7 +177,7 @@ The `docs` attribute now supports `node_color` to customize the node color in th
 
 ## Examples
 
-Add custom node colors to models within subdirectories based on hex codes or a plain color name.
+Add custom `node_colors` to models that support it within subdirectories based on hex codes or a plain color name.
 
 ![Example](../../../../website/static/img/node_color_example.png)