Add --no-unicode option to draw borders in ASCII characters

Close ##1533

man/man1/fzf.1

@@ -174,6 +174,11 @@ A synonym for \fB--layout=reverse\fB
 .TP
 .B "--border"
 Draw border above and below the finder
+
+.TP
+.B "--no-unicode"
+Use ASCII characters instead of Unicode box drawing characters to draw border
+
 .TP
 .BI "--margin=" MARGIN
 Comma-separated expression for margins around the finder.