Re-export all types in `index.js`

Re-export all types in `index.js`

Currently, the types are accessible internally in the library and within `index.js`, but NOT accessible from consumers importing from the `index.js` file. A re-export is required to make the types accessible to end-users.

Additionally, the JSDoc import will only work for types declared at the module scope, so `CSVWriterStatus` was moved to the outer scope.