Add config option for max paragraph width

Hi lynx-devs,

    It would be nice to have a config option that controls the width of the longest allowed line length in a paragraph, i.e. paragraph width. Ideally it would default to something like 70 or 80 characters. It will make it easier to read large bodies of text, and make the appearance of page look more appealing. I know I can change stty setting, but that affects the entire usable screen width not just paragraph width.

Best,

~Robin