Remove the settings for the Example Render module

Problem/Motivation

The Example Render module has settings which change what the module does. This is not what other example modules do.

Proposed resolution

Remove the form elements for those settings shown by the RenderExampleDemoForm class, change its parent class, and rename that class to RenderExampleForm. Furthermore, no code in that module should use those settings; the config file and its schema must be removed too.