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.

2011/toledo/README.md

@@ -18,7 +18,7 @@ Windows](%%REPO_URL%%/2011/toledo/toledo.alt2.c). See [Alternate code](#alternat
 ```
 
 
-## Alternate code
+## Alternate code:
 
 The first alt version, [toledo.alt.c](%%REPO_URL%%/2011/toledo/toledo.alt.c), allows you to reconfigure
 the controls and the dimensions more easily.