Create documentation aimed at "constraint admins"

[tsandall]

We need to produce docs aimed at Kubernetes admins that primarily work with existing templates. For example, we need docs that cover:

• How admins can discover available templates
• How admins can find new templates
• How admins can customize constraints via parameters
• How admins can customize resource matching
• How admins can debug constraints when they're not working
• How admins can check audit status on constraints

[ritazh]

How admins can discover available templates How admins can find new templates How admins can customize constraints via parameters

Moving these to library while others are done.