Replace the term "loop" with the more generic "step". This allows us
to be more flexible and eg. have a step that consists in a single
function call.

Don't include the number of steps in the first comment of the
function, so that we can add or remove steps without having to worry
about keeping that comment in sync.

For the same reason, remove the summary contained in that comment.

Clean up some weird vertical spacing while we're at it.