Update keras_addons.md

Author: krzjoa

addons/keras_addons.md

@@ -1,8 +1,18 @@
 ### Layers
 * [Gradient Reversal Layer](https://github.com/michetonu/gradient_reversal_keras_tf) [[paper]](http://jmlr.org/papers/volume17/15-239/15-239.pdf)
-* [Neural Turing Machine](https://github.com/SigmaQuan/NTM-Keras)
 * [Multiplexer](https://github.com/danielegrattarola/keras-multiplexer)
 * [Graph Attention Network](https://github.com/danielegrattarola/keras-gat)
+* [CoordConv](https://github.com/titu1994/keras-coordconv)
+* [CRF Layer](https://github.com/Hironsan/keras-crf-layer)
+
+#### Neural Turing Machine
+* [Neural Turing Machine](https://github.com/SigmaQuan/NTM-Keras)
+* [Neural Turing Machine](https://github.com/flomlo/ntm_keras)
+
 
 ### Optimizers
 * [L4](https://github.com/danielegrattarola/keras-l4)
+
+
+### Other
+* [Keract](https://github.com/philipperemy/keract) - Activation Maps (Layers Outputs) and Gradients in Keras.