Clock becomes a paragraph by prefixing with not-really-affiliated-keyword

[Tom Alexander]

This test document correctly parses as a clock:
```
CLOCK: [2023-04-21 Fri 19:43]
```

This test document incorrectly parses as a paragraph:
```
#+NAME: foo
CLOCK: [2023-04-21 Fri 19:43]
```

--
Tom Alexander
pgp: https://fizz.buzz/pgp.asc