`\d` in descriptions are triggering errors during Mardown AST building

[andreashaerter]

A desk like

      run_fail2ban_custom_filters:
        description: |
          [...]
          Example:

          ```yaml
          dropbear-complex:
            INCLUDES:
              before: "common.conf"
            Definition:
              _daemon: "dropbear"
              failregex: |-
                ^[Ll]ogin attempt for nonexistent user ('.*' )?from <HOST>:\d+$
                ^[Bb]ad (PAM )?password attempt for .+ from <HOST>(:\d+)?$
          ```

        type: "dict"
        default: {}

containing \d Triggers the following error

Errors:
  • README generation failed: bad escape \d at position 12418 (line 316, column 59)

Escaping it as \\d prevents the error (but there must be no description leading to some kind of parsing / triggering errors). There might be a sanitation issue during Abstract Syntax Tree building.