message: typo fix for rpi.md
diff: @@ -20,7 +20,7 @@ Clone this Tensorflow repository, Run this script at the root of the repository
  ```bash
  ./tensorflow/contrib/lite/download_dependencies.sh
  ```
  -Note than you only need to to this once.
  +Note that you only need to do this once.
  You should then be able to compile:
  ```bash
  @@ -42,7 +42,7 @@ First, clone this TensorFlow repository. Run this at the root of the repository:
  ```bash
  ./tensorflow/contrib/lite/download_dependencies.sh
  ```
  -Note than you only need to to this once.
  +Note that you only need to do this once.
  You should then be able to compile:
  ```bash
  