firebase ext:info doesn't mention events

A documentation issue was opened in firebase extensions:
https://github.com/firebase/extensions/blob/next/firestore-bigquery-export/README.md

We generate our README using `firebase ext:info`, so I am opening an issue here to track it.

### [REQUIRED] Environment info

**firebase-tools:** 13.30.0

**Platform:** macOS

### [REQUIRED] Test case

(any of the official extensions that support events)

### [REQUIRED] Steps to reproduce

1. clone the firebase/extensions repository
2. run `firebase ext:info firestore-bigquery-export --markdown > ./README.md` or similar

### [REQUIRED] Expected behavior

Event information to be included in the extension info

### [REQUIRED] Actual behavior

It doesn't contain any information about the extensions events.