message: Update shape debug string to use explicit tile notation in tiled_layout.md
diff: @@ -9,7 +9,7 @@ work. Errors may be silently ignored.
  </p>
  Figure 1 shows how an array F32[3,5] is laid out in memory with 2x2 tiling. A
  -shape with this layout is written as F32[3,5]{1,0:(2,2)}, where 1,0 relates to
  +shape with this layout is written as F32[3,5]{1,0:T(2,2)}, where 1,0 relates to
  the physical order of dimensions (minor_to_major field in Layout) while (2,2)
  after the colon indicates tiling of the physical dimensions by a 2x2 tile.
  