Nova resources requiring slugs should autofill based on title

[chx2]

Nova resources in this package that require slugs should mimic resources in https://github.com/tipoff/locations and https://github.com/drewroberts/blog that autofill slugs when providing input for a field such as title. It can be somewhat frustrating to a non-technical user on trying to figure out what might be acceptable for a slug field if they have to fill it out manually.