* Remove definitely unused attributes
* Refactor and remove unused attributes
* Add parentheses
* Prevent alt tag from having Liquid tags inside
* Add test
* Remove more unused attributes
* Scrub any valid attributes
* Remove unused tags and add more tests
* Remove <i> tag; <em> is used by parser
* Remove <center> b/c it's deprecated though still valid
* <cite> is a safe tag and used by some
* Eh I changed my mind about center lol
* Add underline <u> back in
* Don't allow width changes
* Use frozen constant for regex
* Use #remove over #gsub
* Added <kbd> tag support to markdown editors in article posts and comments.
* Fixed typo in test.
* Fixed test - now compares against inner html.
* Removed .showpage-signi-cta as dead code was reinstated accidentally via git merge.
* Use sass placeholder as no need to output the .kbd class in the css.
* Reinstated original css as accidentally changed with merge.
* Lint and clean up github issue styles
* Use heredoc HTML for easier formatting
* Add better error handling for 404 github issues
* Use custom sanitizer for markdown render
* Refactor unless to ternary
* Rename file and tighten up sanitization
* Fix codepen and instagram tag styling
