Typescript type support

[mentos1386]

Hey, awesome project. One thing missing are typescript type definitions. It looks the code base is quite small, would it be worth to "rewrite" in to typescript?

I guess the only type definition missing is for the export itself. That could be written as a d.ts definition without any rewrite. As the change itself is very small.

[djMax]

I rewrote this here for the latest otel apis, latest node APIs and in TS: https://github.com/sesamecare/opentelemetry-node-metrics

[fullammo]

Great work boys! @mentos1386 @djMax Thanks for your efforts. will come back with my feedback as soon as i'm able to try it out in action! Btw, shouldn't this be part of the https://github.com/open-telemetry/opentelemetry-js-contrib repository? Seems like a great addition.

[mentos1386]

@fullammo yes, it would be nice if it would be in opentelemetry-js-contrib. There has been some work done on that already, but nothing completed open-telemetry/opentelemetry-js-contrib#1106