fix typo in tilt-settings.yaml example

Author: apricote

docs/book/src/developer/tilt.md

@@ -43,7 +43,7 @@ Next, create a `tilt-settings.yaml` file and place it in your local copy of `clu
 default_registry: gcr.io/your-project-name-here
 provider_repos:
 - ../cluster-api-provider-aws
-enable_providers": 
+enable_providers:
 - aws
 - docker
 - kubeadm-bootstrap