Function toKey

toKey(identity: Identity): string
Compute composite key from identity fields.

Under NIP-5D v0.1.0, the key is 'dTag:hash' (pubkey is ignored).
Parameters
- identity: Identity
  Napplet identity
Returns string
Composite key string 'dTag:hash'
Example
```
toKey({ dTag: 'chat', hash: 'ff00' })
// => 'chat:ff00'
```
- Defined in check.ts:24