update docs

Author: ben-schwen

man/fread.Rd

@@ -16,7 +16,7 @@ stringsAsFactors=FALSE, verbose=getOption("datatable.verbose", FALSE),
 skip="__auto__", select=NULL, drop=NULL, colClasses=NULL,
 integer64=getOption("datatable.integer64", "integer64"),
 col.names,
-check.names=FALSE, encoding="unknown",
+check.names=FALSE, encoding="UTF-8",
 strip.white=TRUE, fill=FALSE, blank.lines.skip=FALSE, comment.char="",
 key=NULL, index=NULL,
 showProgress=getOption("datatable.showProgress", interactive()),