motivation: adjust format to xcode format
changes:
* update .swiftformat no-indent setting and run formatter
* update test generation script to match correct format
motivation: some metrics backend prefer to be given a hint about the preferred display unit (seconds, milliseconds, etc) to drive the ux
changes: add a `preferedUnit` to TimerHandler (and `TimeUnits`) to capture the prefer display unit
motivation: allow middleware libraries better control of metric object lifecycle to reduce potential memory footprint when using metrics libraries that use some kind of registry or cache (eg polling backends)
changes:
* Introduce metric.destroy() to enable lifecycle management
* Add destroy functions to example impl in readme
* prepare to release
motivation: the sswg voted to adopt the API. this is to prepare to a release
changes:
* rewrite readme
* add API docs
* add utilitiy scripts and docker setup for CI
* adjust linux tests