Markdown validation according to templates

[vstirbu]

Motivation

The modelcard contains longer descriptions that cannot be properly handled with basic string properties. Embedding markdown formatted content for these properties has the advantage that the author can use advanced formatting capabilities while still being compatible with the schema type.

We'll follow the approach, pioneered by GitHub with issue template, to guiding data scientist to contribute structured descriptions instead of free form text:

model_details:
    version:
        name: 1.2.3 # follow semantic versioning
        date: 2021-12-15 # release date
    documentation: |
        <!-- markdown description of the model -->
        ...
model_parameters:
    data:
        - name: training
          description: |
            <!-- markdown description of the dataset -->
            ...
            ## Justification
            
            The section provides justification why the training dataset
            is enough to fulfill the clinical validation.
            ...

Templates validation

Develop custom function to validate that the markdown content provided by the developer/data scientist follows the provided template.

The rule can look like:

functions:
  - markdownValidator
rules:
  my-rule:
    message: "{{error}}"
    given: "$.documentation"
    then:
      function: "markdownValidator"
      functionOptions:
        value: |
          ## Header 1
          ...

          ## Header 2