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.

2013/hou/README.md

@@ -75,8 +75,6 @@ even needing to create a temporary file but as the author refers to it and its
 uses it can still be generated to follow along.
 
 
-
-
 ## Author's remarks:
 
 ### Using hou