format headers

We move `tmp/format-headers.sh` into `bin/format-headers.sh`.

We also add a few missing empty lines to `README.md`.

We add `bin/format-headers.sh` to the `bin/README.md`.

We run `bin/format-headers.sh` to perform the above.

Performed `make www` to accomplish the above and to test under macOS.

2020/otterness/README.md

@@ -53,7 +53,7 @@ with the MIDI "SMF" file format.
 entry](https://www.nathanotterness.com/2021/04/obfuscated_c_2020.html).
 
 
-## Alternate use:
+### Alternate use:
 
 Use `prog.alt` as you would `prog`.