[SavedModel Fingerprinting] Add information about the fingerprint to the SavedModel guide.

Starting in TF 2.11, all SavedModels written using `tf.saved_model.save` will contain a `fingerprint.pb` file.

tensorflow/community#415

PiperOrigin-RevId: 520938759

Author: BlaziusMaximus

site/en/guide/saved_model.ipynb

@@ -354,7 +354,9 @@
       "source": [
         "The `assets` directory contains files used by the TensorFlow graph, for example text files used to initialize vocabulary tables. It is unused in this example.\n",
         "\n",
-        "SavedModels may have an `assets.extra` directory for any files not used by the TensorFlow graph, for example information for consumers about what to do with the SavedModel. TensorFlow itself does not use this directory."
+        "SavedModels may have an `assets.extra` directory for any files not used by the TensorFlow graph, for example information for consumers about what to do with the SavedModel. TensorFlow itself does not use this directory.\n",
+        "\n",
+        "The `fingerprint.pb` file contains the [fingerprint](https://en.wikipedia.org/wiki/Fingerprint_(computing)) of the SavedModel, which is composed of several 64-bit hashes that uniquely identify the contents of the SavedModel. The fingerprinting API is currently experimental, but `tf.saved_model.experimental.read_fingerprint` can be used to read the SavedModel fingerprint into a `tf.saved_model.experimental.Fingerprint` object."
       ]
     },
     {