schema-salad-doc produces duplicated attribute entry when inheriting from parent

[kinow]

Ref: common-workflow-language/cwl-v1.2#166 (comment)

The latest release of schema-salad allows for overriding the documentation of a parent type in a child type. i.e.

- name: Parent
  doc: |
    Parent record
  documentRoot: true
  docChild:
    - "#Child"
  type: record
  fields:
    - name: id
      jsonldPredicate:
        _id: "#id"
      type: int
      doc: Parent ID

- name: Child
  doc: |
    Child record
  type: record
  extends: Parent
  fields:
    - name: id
      jsonldPredicate:
        _id: "#id"
      type: int
      doc: Child ID

Note the id field has a different doc value in the child type. However, running this schema through schema-salad, it prints the id field twice in the child.

(venv) kinow@ranma:~/Development/python/workspace/schema_salad$ schema-salad-tool --print-doc schema_salad/tests/inherited-attributes.yml > /tmp/test.html 
/home/kinow/Development/python/workspace/schema_salad/venv/bin/schema-salad-tool Current version: 8.3.20220622140130