[error] "Price" must be defined in MODULE_NAME.field_type_categories.yml

Problem/Motivation

When using this module with Drupal 11, I encountered a fatal error when attempting to add a new field to a content type:
"Price" must be defined in MODULE_NAME.field_type_categories.yml

Proposed resolution

This seems to be a result of using the label for the category instead of the machine name, in the field's metadata.