docs: def injectable_definition(inj_name):
      """
      Get the source of an injectable function.
  
      If an injectable is a registered Python variable and not a function
      then all that is returned is {'type': 'variable'}.
  
      If the column is a registered function then the JSON returned has keys
      "type", "filename", "lineno", "text", and "html". "text" is the raw
      text of the function, "html" has been marked up by Pygments.
  
      """
      inj_type = orca.injectable_type(inj_name)
  
      if inj_type == 'variable':
          return jsonify(type='variable')
      else:
          filename, lineno, source = \
              orca.get_injectable_func_source_data(inj_name)
          html = highlight(source, PythonLexer(), HtmlFormatter())
          return jsonify(
              type='function', filename=filename, lineno=lineno, text=source,
              html=html)