[feature] Add filters for dealing with semconv attribute registry

[jsuereth]

We' like a set of filters that allow us to interact with the id of an attribute_group.

Specifically:

• attribute_registry_namespace: Converts registry.{namespace}.{other}.{components} to {namespace}
• attribute_registry_title: Converts registry.{namespace}.{other}.{components} to {Namespace} (title case the namespace).
• attribute_registry_file: Converts registry.{namespace}.{other}.{components} to attributes-registry/{namespace}.md (kebab-case namespace).

[lquerel]

Implemented in #136