[PD] Filter help patches typos

[Peter P.]

Hi,

just want to mention two typos:

rzero~-help.pd mentions that this was a "recursive" filter. Maybe this
is a copy+paste error from rpole~-help?

The difference equation in biquad~-help.pd gives an
	x[n-3]
instead of
	x[n-2]

cheersz, P