chore(package): use dist dir for publish and entrypoint

[steebchen]

Change the behaviour of the dist directory:

• set dist/index.js as entrypoint
• set files to only include the dist directory on publish

This makes development easier because the entrypoint is the same when using npm/pnpm link.

The only downside is that imports for the end user would include the dist directory (e.g. @hatchet-dev/typescript-sdk/dist/foo/bar), but everything should be imported from the root package anyway.