Update README (#442)

* Update README

Added links to the tutorials for creating custom scatterers.

* Update README

* Update README.md

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Co-authored-by: Alex <[email protected]>

Author: mirjagranfors

README.md

@@ -97,6 +97,14 @@ Here you find a series of notebooks that give you an overview of the core featur
 
   Using PyTorch gradients to fit a Gaussian generated by a DeepTrack2 pipeline.
 
+- DTGS171A  **[Creating Custom Scatterers](https://github.com/DeepTrackAI/DeepTrack2/blob/develop/tutorials/1-getting-started/DTGS171A_custom_scatterers.ipynb)** <a href="https://colab.research.google.com/github/DeepTrackAI/DeepTrack2/blob/develop/tutorials/1-getting-started/DTGS171A_custom_scatterers.ipynb"><img src="https://colab.research.google.com/assets/colab-badge.svg"></a>
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+  Creating custom scatterers of arbitrary shapes.
+
+- DTGS171B  **[Creating Custom Scatterers: Bacteria](https://github.com/DeepTrackAI/DeepTrack2/blob/develop/tutorials/1-getting-started/DTGS171B_custom_scatterers_bacteria.ipynb)** <a href="https://colab.research.google.com/github/DeepTrackAI/DeepTrack2/blob/develop/tutorials/1-getting-started/DTGS171B_custom_scatterers_bacteria.ipynb"><img src="https://colab.research.google.com/assets/colab-badge.svg"></a>
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+  Creating custom scatterers in the shape of bacteria.
+
 # Examples
 
 These are examples of how DeepTrack2 can be used on real datasets: