v1.4.0

• Add OAS 3.1 support, cross-version warnings, and fix nullable spacing, by @dcode.
• Fix MARKDOWN style table separators to use minimum 3 hyphens (issue #39), reported by @michael-nok.
• Fix #45: add support for displaying descriptions of schema properties, reported by @Maia-Everett.
• Fix #30: raise an error when trying to generate output from an older Swagger v2 specification file (these were never supported as there was never a /mk/v2/ namespace, intentionally).
• Fix #35: group response codes in a tab group on MkDocs output, reported by @Andre601.
• Fix #47: remove wordwrap filters from all templates as they break links and mermaid chart code blocks in descriptions, reported by @ElementalWarrior.
• Fix #49: support $ref values of the form file.yaml#/fragment/path (external file with JSON Pointer fragment), reported by @mbklein.
• Fix #55: jsonSchemaDialect is not required and should not have a default value.
• Fix #60: resolve $ref values in response headers pointing to #/components/headers/... to avoid UndefinedError when rendering response tables, reported by @copiousfreetime.
• Fix #64: use examples array (JSON Schema draft 6+) as a fallback for auto-generated response examples; also use enum values as examples for all scalar types (integer, number, boolean), reported by @jan-ldwg.