It's easy to find double paragraph marks, do the find thing. When you do it it will bring a dialog box showing the number of times it found them. Then you do a replace. Sometimes it can be a 'paragraph mark, space, paragraph mark.
@mogui You can make a quick example for yourself. Take any PDF and do the 'convert to text'. Then open the document with word, it's messed with them.
@RWood You're right it's replace with a space.
Writing scripts is totally 'alienite' to most of us, we have to make do with tools already offered.