[BUG] Browser availability notated in the WPT scores section can lead to contradictory messaging

**Describe the bug**
On a feature overview page under the "Web platform test scores" section, we have cards for each browser, with big text showing the WPT score. Below that, we also show when the feature became available in that browser.

This can lead to situations where a feature IS available in a browser, but DOES NOT have a WPT score, confusingly leading to messaging like this:

```
N/A
Available since YYYY-MM-DD
```

(N/A stands for "not available")

At a glance, it might seem like the feature is not available in this browser, even though it is.

**To Reproduce**
Steps to reproduce the behavior:

1. Go to https://webstatus.dev/features/jpegxl
2. Look at the Safari iOS card

**Expected behavior**

I would expect browser availability information to be more prominent and easily discoverable than the WPT scores.

Other Baseline apps use things like icons, colors, or listing browser versions to signify browser support. For example:

These UI patterns more clearly communicate which browsers support it and which don't.