add turtle benchmark and reorganize (#259)

benchmarks/gradient-autoview.nu

@@ -0,0 +1,20 @@
+# this script will print a blue gradient on the screen
+# it's intended to simulate nushell v0.44 with autoview
+
+let height = (term size).rows - 3 # calculate height
+let width = (term size).columns - 5  # calculate width
+let stamp_start = $width * 1.25 # calculate where to start Nu stamp
+let stamp_end = $width * 1.3125 # calculate where to stop Nu stamp
+let stamp = 'Nu'
+seq 0 $height | par-each { # create these in parallel
+    let row_data = (seq 0 $width | each { |col|
+        let fgcolor = 2 + 2 * $col
+        if $fgcolor > $stamp_start && $fgcolor < $stamp_end {
+            $"(ansi -e '48;2;0;0;')($fgcolor)m($stamp)(ansi -e '0m')"
+        } else {
+            $"(ansi -e '48;2;0;0;')($fgcolor)m (ansi -e '0m')"
+        }
+    } | str collect)
+    $"($row_data)" | table
+    $nothing
+} | compact