What is the host key for exe.dev?

How to verify you're connecting to exe.dev

When you first `ssh exe.dev` you are looking for the fingerprint:

```
SHA256:JJOP/lwiBGOMilfONPWZCXUrfK154cnJFXcqlsi6lPo.
```

Ensuring that fingerprint is displayed the first time means that
and all future connections from that device are going directly
to `exe.dev`.