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.

1989/jar.2/README.md

@@ -37,6 +37,7 @@ It has no error recovery, and performs rather poorly in a number of cases.  Even
 so, placing all this functionality in such a small, densely packed program, is
 impressive enough to win the `Best of Show` award.
 
+
 ## Author's remarks:
 
 This program implements a Lisp interpreter in 1465 bytes of source.