ClusterAnnotationStyle removed. Documentation update needed.

[joaomvfsantos]

New Issue Checklist

• [x] I updated Cluster to the latest version.
• [x] I read the Contribution Guidelines.
• [x] I read the documentation.
• [x] I searched for existing GitHub issues.

Issue Description

ClusterAnnotationStyle has been removed. Documentation still refers to this removed API. Needs update. At the moment the only way to guess more or less how this works is to dig into the Examples code.

Thank you for you work!

Environment

• iOS Version: all
• Device(s): all

[efremidze]

Thanks, I'll update now.