Cloudflare SFU API documentation update

### Existing documentation URL(s)

https://developers.cloudflare.com/realtime/static/calls-api-2024-05-21.yaml

### What changes are you suggesting?

Latest documentation? But here are some specific things missing

`/apps/{appId}/sessions/new` doesn't seem to introduce `sessionDescription` anywhere, even though that it is a valid parameter (`requestBody`).

For `/apps/{appId}/sessions/{sessionId}/tracks/new` I tried the example
```
push_track_without_an_offer:
description: SFU can generate an offer to push a local track
value:
tracks:
- location: local
trackName: mic-1
kind: "audio"
```
but it doesn't work. For some reason, using `bidirectionalMediaStream: true` makes it work, but that generates a `sendrecv` transceiver while `bidirectionalMediaStream: false` (or unset) fails with backend error - I believe the example is implying a one way transceiver.

### Additional information

I don't also see any information with regard to Trickle ICE so I'm guessing it is not supported.