Make the types module so users can install @types/tedious-connection-pool2

[700software]

We can probably just copy this straight from @types/tedious-connection-pool original

But I'd like types to be part of our own repo, so changes can be maintained and part of our same versioning. We can put them in a types directory I suppose. Alternatively files can be ported from .js to .ts but that might be more work.

[Nedlinin]

Another option would be to just generate own using the TS compiler.

https://www.typescriptlang.org/docs/handbook/declaration-files/dts-from-js.html