docs: add Compositekey lookup

docs/content/1.guide/3.relationships/3.one-to-many.md

@@ -198,7 +198,7 @@ class Post extends Model {
 }
 ```
 
-Though posts do not contain a country_id column, the `hasManyThrough` relation provides access to a country's posts. To perform this query, Vuex ORM inspects the `country_id` on the intermediate User model. After finding the matching user IDs, they are used to query the Post model.
+Though posts do not contain a country_id column, the `hasManyThrough` relation provides access to a country's posts. To perform this query, Pinia ORM inspects the `country_id` on the intermediate User model. After finding the matching user IDs, they are used to query the Post model.
 
 The first argument passed to the `hasManyThrough` method is the final model we wish to access, while the second argument is the intermediate model. The third argument is the name of the foreign key on the intermediate model. The fourth argument is the name of the foreign key on the final model.
 

docs/content/1.guide/4.repository/2.retrieving-data.md

@@ -76,6 +76,19 @@ const user = useRepo(User).find(1)
 const user = useRepo(User).where('active', true).first()
 ```
 
+### Retrieving models with composite keys
+
+You can query a record that has composite primary keys by passing the key as a string like so:
+
+```js
+// Retrieve a model by its primary key.
+const user = useRepo(User).find('[1,2]')
+
+// Retrieve the first model matching the query constraints.
+const user = useRepo(User).whereId('[1,2]').first()
+```
+
+
 ## Where Clauses
 
 You may use the `where` method to add `where` clauses to the query. The most basic call to `where` requires 2 arguments. The first argument is the name of the field. The second argument is the value to evaluate against the field.

docs/content/1.guide/4.repository/5.deleting-data.md

@@ -66,3 +66,15 @@ You can also run a delete statement on a set of records. In this example, we wil
 ```js
 useRepo(User).where('active', false).delete()
 ```
+
+### Deleting models with composite keys
+
+You can delete a record that has composite primary keys by passing the key as a string like so:
+
+```js
+// Delete using destroy
+useRepo(User).destroy('[1,2]')
+
+// Delete by query 
+useRepo(User).whereId('["hi","there"]').delete()
+```