message: Update demo_ios.md
diff: @@ -120,7 +120,7 @@ model = tflite::FlatBufferModel::BuildFromFile([graph_path UTF8String]);
  Behind the scenes, the model is loaded as a memory-mapped file. It offers faster
  load times and reduce the dirty pages in memory.
  -Construct a `BuiltinOpResolver` to use the TensorFliw Lite buildin ops. Then,
  +Construct a `BuiltinOpResolver` to use the TensorFlow Lite buildin ops. Then,
  create the interpreter object using `InterpreterBuilder` that takes the model
  file as argument as shown below.
  