As the OSS project only controls the mermaid.live domain, we're adding an env variable to let anyone who is self hosting live editor to set their own privacy policy, or to hide the button if they want to.
This commit adds support for generating links to be rendered with
[Kroki](https://kroki.io) compatible renderer. Apart from supporting many other
diagram formats, it directly benefits Mermaid editor because it generates much
shorter URLs (due to the compression).
Custom Kroki URL can be configured through environment variable if you want to
use self-hosted instance of Kroki.
Sidharth Vinod