Add tensorflow-haskell-deptyped example (#174)

https://github.com/tensorflow/haskell/issues/156

README.md

@@ -120,7 +120,37 @@ No exportable Nix package will appear, but local development is possible.
 
 # Related Projects
 
+## Statically validated tensor shapes
+
 https://github.com/helq/tensorflow-haskell-deptyped is experimenting with using dependent types to statically validate tensor shapes. May be merged with this repository in the future.
 
+Example:
+
+```haskell
+{-# LANGUAGE DataKinds, ScopedTypeVariables #-}
+
+import Data.Maybe (fromJust)
+import Data.Vector.Sized (Vector, fromList)
+import TensorFlow.DepTyped
+
+test :: IO (Vector 8 Float)
+test = runSession $ do
+  (x :: Placeholder "x" '[4,3] Float) <- placeholder
+
+  let elems1 = fromJust $ fromList [1,2,3,4,1,2]
+      elems2 = fromJust $ fromList [5,6,7,8]
+      (w :: Tensor '[3,2] '[] Build Float) = constant elems1
+      (b :: Tensor '[4,1] '[] Build Float) = constant elems2
+      y = (x `matMul` w) `add` b -- y shape: [4,2] (b shape is [4.1] but `add` broadcasts it to [4,2])
+
+  let (inputX :: TensorData "x" [4,3] Float) =
+          encodeTensorData . fromJust $ fromList [1,2,3,4,1,0,7,9,5,3,5,4]
+
+  runWithFeeds (feed x inputX :~~ NilFeedList) y
+
+main :: IO ()
+main = test >>= print
+```
+
 # License
 This project is licensed under the terms of the [Apache 2.0 license](LICENSE).