v1.5.0

Updates

1. enhance: openapi3edit: refactor to OperationEditor
2. fix: mkdocs: typos
3. streamline: openapi3: use implicit type
4. enhance: openapi3: param names for understanding
5. enhance: openapi3: constants
6. cleanup: openapi3edit: remove dupe function
7. streamline: openapi3: update code for ioutilmore.ReadDirMore()
8. docs: mkdocs: update oas3lint cli
9. feat: cmd/oas3lint: add severity flag
10. cleanup: openapi3lint: clean up code
11. docs: openapi3int: update custom rules
12. docs: mkdocs: fix repo link
13. docs: mkdocs: update mkdocs.yml
14. docs: openapi3lint: add mkdocs docs