Horizontal padding in Element Nightly room timeline limiting chat width/size

### Steps to reproduce

1. Where are you starting? What can you see?

Opened a chat on Element Nightly. In room timeline there is a large amount of padding to the left of the avatar/text and to the right.

As if it's got:
```
#timeline {
max-width: ...px;
margin-left: auto;
margin-right: auto;
}
```

Is this intended or a bug? I feel like my screen real estate is being wasted :(

Please let me know if logs/anything else would help.

### Outcome

#### What did you expect?

The text to expand to the full width of the container.

#### What happened instead?
The text is contained in a narrow container.

### Operating system

macOS

### Application version

Element Nightly 2022031701

### How did you install the app?

_No response_

### Homeserver

Synapse

### Will you send logs?

No