Create an article linter program

[briandfoy]

trafficstars

This program would check an article file to ensure everything is as it should be:

• [x] The meta data are well-formed
• [ ] Meta data are complete
• [ ] The content is valid markdown
• [ ] The author data is in the repo
• [ ] The images are in the repo
• [ ] Any external links are good

extract_article_links - short codes ``` " tchrist quoting ` runaway code line (tchrist article) - unclosed (maybe limit length of stuff on the inside)

[briandfoy]

I started the bin/article-lint in the remove-authors-from-tags branch (2889655831bd285ff8648ef5b9e8e2d0c06f05ce)