Prezmanifest

* uses updated labelify
* improved date handling for versioning
* accepts date or dateTime values
* allows a conformance claim in a manifest to indicate a user-supplied SHACL validator


...
dcterms:conformsTo "my-shacl-validator.ttl" ;
...

* implements the `sync` function
* updated documentation
* more internal functions handed off to the [kurra](https://github.com/kurrawong/kurra) toolkit

* all documentation re-written to align with the new CLI
* README examples too

* moved CLI to using Typer
* consistent CLI options
* fixed some small bugs
* test coverage of CLI incomplete but improved on 0.6.0

* exposes each PM function as a named command line script
* fixes a Conformance Test validation bug

* handles all aspects of Issue 7