Rename param to fix auto doc regex

[cjhaas]

I was reading the docs for the Assertion::count() method and they incorrectly say:

Assertion::count(array|\Countable $countable, array|\Countable $count);

The second param should be an int however the auto doc generator's RegEx greedily takes the param type for the first item that starts with the param name. In this case, $countable always wins because it starts with $count.

In the long run the doc generator should probably be adjusted but in the short term, since $value is used elsewhere I thought this would be a simpler change.

[rquadling]

I've fixed the generator. Just needed a \b in the regex.