Modernisation

[nickpack]

Not sure how well used this lib is now, but it fits the bill for some work I am currently doing so I have decided to lightly refactor it so that it works in a more modern stack

• Minor refactor, targeting ES2021
• Replaced jshint with eslint (just the default set of rules for now) - no inspections failing
• All vulnerable dependencies updated and npm audit is now showing no issues.
• All tests passing
• Examples tweaked to use import rather than require

I have a bit more work to do to modernise the code fully, but it works in its current state and the test suite is passing.

This will obviously be a pretty significant backwards compatability break so should be considered with caution.