message: Fix langref code snippet - NFC
  Closes
diff: @@ -811,17 +811,25 @@ exposed to codegen but one may query the rank of an unranked memref (a special
  op will be needed for this purpose) and perform a switch and cast to a ranked
  memref as a prerequisite to codegen.
  -Example ```mlir {.mlir} // With static ranks, we need a function for each
  -possible argument type %A = alloc() : memref<16x32xf32> %B = alloc() :
  -memref<16x32x64xf32> call @helper_2D(%A) : (memref<16x32xf32>)->() call
  -@helper_3D(%B) : (memref<16x32x64xf32>)->()
  -
  -// With unknown rank, the functions can be unified under one unranked type %A =
  -alloc() : memref<16x32xf32> %B = alloc() : memref<16x32x64xf32> // Remove rank
  -info %A_u = memref_cast %A : memref<16x32xf32> -> memref<*xf32> %B_u =
  -memref_cast %B : memref<16x32x64xf32> -> memref<*xf32> // call same function
  -with dynamic ranks call @helper(%A_u) : (memref<*xf32>)->() call @helper(%B_u) :
  -(memref<*xf32>)->() ```
  +Example
  +```mlir {.mlir}
  +// With static ranks, we need a function for each
  +// possible argument type
  +%A = alloc() : memref<16x32xf32>
  +%B = alloc() : memref<16x32x64xf32>
  +call @helper_2D(%A) : (memref<16x32xf32>)->()
  +call @helper_3D(%B) : (memref<16x32x64xf32>)->()
  +
  +// With unknown rank, the functions can be unified under one unranked type
  +%A = alloc() : memref<16x32xf32>
  +%B = alloc() : memref<16x32x64xf32>
  +// Remove rank info
  +%A_u = memref_cast %A : memref<16x32xf32> -> memref<*xf32>
  +%B_u = memref_cast %B : memref<16x32x64xf32> -> memref<*xf32>
  +// call same function with dynamic ranks
  +call @helper(%A_u) : (memref<*xf32>)->()
  +call @helper(%B_u) : (memref<*xf32>)->()
  +```
  The core syntax and representation of a layout specification is a
  [semi-affine map](Dialects/Affine.md#semi-affine-maps). Additionally, syntactic
  