feat: Export `Options` interface from type declarations.

[typhonrt]

In one of my projects I use comment-parser and would like to expose the parser options from my library function. Currently the types provided from ./lib/index.d.ts does not export Options from ./lib/parser/index.d.ts.

While fixing this issue perhaps it is a good time to update the exports fields in package.json adding a types export condition with the types for each sub-path export as well.

I'd be glad to take a look at this if necessary.