mdl 0.6.0

Added

• There are now CONTRIBUTING.md and MAINTAINERS.md docs
• There is now a .pre-commit-hooks.yaml for those who want to use pre-commit.com

Changed

• Ignore blank line after front matter #248
• Only import JSON when necessary #231
• Use newere mixlib-cli #265
• Nicer error message when activating nonexistent rule #246
• Fix documentation on ignore_front_matter #241
• Update docs to use "MY" prefix for custom rule example #245
• Fix crash in MD039 when the link text is empty #256
• Reference Node.js markdownlint #229
• Added table of contents to RULES.md for easier navigation #232
• Fix typos in MD046 docs #219
• Fixed MD036 crash #222

Removed