Update contributing guide for models
Updates the contributing guide highlighting that the SDK is unable to take model change PRs directly, but to create an issue instead.
@@ -64,6 +64,11 @@ Please be aware of the following notes prior to opening a pull request:
SDK's test coverage percentage are unlikely to be merged until tests have
been added.
+5. The JSON files under the SDK's `models` folder are sourced from outside the SDK.
+ Such as `models/apis/ec2/2016-11-15/api.json`. We will not accept pull requests
+ directly on these models. If you discover an issue with the models please
+ create a Github [issue](issues) describing the issue.
+
### Testing
To run the tests locally, running the `make unit` command will `go get` the
