publish well-formulated and concise types

[tmc]

Preflight Checklist

• [X] I have searched the issue tracker for a feature request that matches the one I want to file, without success.

What package is this feature request for?

rrweb

Problem Description

Today the types that define the payloads the rrweb ecosystem operates over are a bit spread out which makes them not super accessible to other language environments.

Proposed Solution

Tidy up and publish a small set of straightforward types.

Alternatives Considered

Not doing so.

Additional Information

No response