jekyll_strict_front_matter

By default, if a page or a post in a Jekyll site has a syntax error in the front matter, Jekyll logs an error, does not render anything for the given page, and continues. The result is a site without any content for the page with the syntax error. This can be confusing for people who build sites without looking at the CLI, such as those of us whose sites build in a CI. In these cases, we may wish for our build to fail if there are front matter syntax errors. [This PR](https://github.com/jekyll/jekyll/pull/5832/files) seeks to add a config option for that, but in the meantime this plugin exists to fill the gap. This plugin may also be used to add the option to sites using an older version of Jekyll.