v2.1.4: export md and binaries built in CI

This release adds a new feature to art export, art export md.

In addition, it allows for several settings to control how the markdown is exported, as well as add code links in the WebUI. Not all paths on the web yet render-able as code links, and the settings are not yet documented. Expect further improvements in future releases.

This is the first release since before v2.0.0 (the complete rewrite) that was built and uploaded by Travis. Windows support is close as well.

Internally, there were several changes:

• Changed the internal crates to use a workspace
• Refactored to add Project.settings, which will make it much easier to configure new settings via .art/settings.toml
• General code cleanup