sandpaper 0.5.1

What's Changed

This release adds an enumeration of chapters/episodes to the sidebar and updates the workflows to be faster by using the pre-installed version of R.

• update check to v2 of actions by @zkamvar in #275
• add chapter/episode number to sidebar by @zkamvar in #277
• Update workflows by @zkamvar in #279

Full Changelog: 0.5.0...0.5.1