v4.0.0

There were no functional changes in this release, all behaviour is the same.

Breaking changes since v3.0.2

• Dropped support for NodeJs versions less than v16
• Moved the command-line tool out into a separate project.

Misc improvements

• Some dependency tree optimisations
• Added a trivial web front-end to demonstrate isomorphism.
  • From the root of the project, launch a web server (e.g. local-web-server) then navigate to the examples/web folder to view the front-end.