Update js-sdk docs for google cloud functions with firebase.

[chargome]

Core or SDK?

Platform/SDK

Which part? Which one?

@sentry/google-cloud-serverless

Description

There is a note that firebase cloud functions are currently not supported but no further guidance on how to set up sentry in this case.

see: getsentry/sentry-javascript#12738

Suggested Solution

We should provide an example or section etc. that showcases how to set up sentry with firebase (manually).

[JPeer264]

closed as we now have an integration.

ref #15247