FILL  (CTRL/F)
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 Performs a word fill on the select range.  A word fill reformats a block of text
 so that as many full words as possible are placed on each line without exceeding
 the right margin.  You can set the right margin with the SET WRAP command.  If
 it is not set, the default is the terminal width - 1.  For purposes of the FILL
 command, only spaces are used as word delimiters.