Semantic model configs in project.yml (#4144)

## What are you changing in this pull request and why?

Semantic model configs for dbt project.yml

Closes: #3997

## Checklist

Uncomment if you're publishing docs for a prerelease version of dbt
(delete if not applicable):
- [x] Add versioning components, as described in [Versioning
Docs](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-entire-pages)

- [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.
- [x] Add a checklist item for anything that needs to happen before this
PR is merged, such as "needs technical review" or "change base branch."

website/docs/docs/build/semantic-models.md

@@ -108,6 +108,29 @@ semantic_models:
         type: categorical
 ```
 
+<VersionBlock firstVersion="1.7">
+
+Semantic models support configs in either the schema file or at the project level. 
+
+Semantic model config in `models/semantic.yml`:
+```yml
+semantic_models:
+  - name: orders
+    config:
+      enabled: true | false
+      group: some_group
+```
+
+Semantic model config in `dbt_project.yml`:
+```yml
+semantic_models:
+  my_project_name:
+    +enabled: true | false
+    +group: some_group
+```
+
+</VersionBlock>
+
 ### Name 
 
 Define the name of the semantic model. You must define a unique name for the semantic model. The semantic graph will use this name to identify the model, and you can update it at any time. Avoid using double underscores (__) in the name as they're not supported.