Provide an example of meta in dbt_project (#2270)

## Description & motivation
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It took me a while to figure out why my `meta` tag wasn't being captured
in the dbt_project file. I needed it nested under the `config` block. I
think it would have helped if there was an example of that.

(I deleted all the checklists as it didn't seem like they were needed
for this PR)

---------

Co-authored-by: mirnawong1 <89008547+mirnawong1@users.noreply.github.com>
Co-authored-by: Leona B. Campbell <3880403+runleonarun@users.noreply.github.com>

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

@@ -278,4 +278,19 @@ select 1 as id
 ```
 
 </File>
+
+### Assign owner in the dbt_project.yml as a config property
+
+<File name='models/my_model.sql'>
+
+```yml
+models:
+  jaffle_shop:
+      materialized: table
+      config:
+        meta:
+          owner: "@alice"
+```
+
+</File>