Fix typo in Google VertexAIModel documentation (mkdocs) (#772)

Author: chris-dare

docs/models.md

@@ -264,7 +264,7 @@ agent = Agent(model)
 Internally this uses [`google.auth.default()`](https://google-auth.readthedocs.io/en/master/reference/google.auth.html) from the `google-auth` package to obtain credentials.
 
 !!! note "Won't fail until `agent.run()`"
-    Because `google.auth.default()` requires network requests and can be slow, it's not run until you call `agent.run()`. Meaning any configuration or permissions error will only be raised when you try to use the model. To for this check to be run, call [`await model.ainit()`][pydantic_ai.models.vertexai.VertexAIModel.ainit].
+    Because `google.auth.default()` requires network requests and can be slow, it's not run until you call `agent.run()`. Meaning any configuration or permissions error will only be raised when you try to use the model. To initialize the model for this check to be run, call [`await model.ainit()`][pydantic_ai.models.vertexai.VertexAIModel.ainit].
 
 You may also need to pass the [`project_id` argument to `VertexAIModel`][pydantic_ai.models.vertexai.VertexAIModel.__init__] if application default credentials don't set a project, if you pass `project_id` and it conflicts with the project set by application default credentials, an error is raised.