add demo notebooks

Author: Matt Sokoloff

examples/README.md

@@ -65,3 +65,5 @@
 | --------------------------- | --------------------------------- | ------------ |
 | Model Diagnostics Guide  | [Github](model_diagnostics/model_diagnostics_guide.ipynb) | [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/Labelbox/labelbox-python/blob/develop/examples/model_diagnostics/model_diagnostics_guide.ipynb) |
 | Model Diagnostics Demo  | [Github](model_diagnostics/model_diagnostics_demo.ipynb) | [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/Labelbox/labelbox-python/blob/develop/examples/model_diagnostics/model_diagnostics_demo.ipynb) |
+| Custom Metrics Basics  | [Github](model_diagnostics/custom_metrics_basics.ipynb) | [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/Labelbox/labelbox-python/blob/develop/examples/model_diagnostics/custom_metrics_basics.ipynb) |
+| Custom Metrics Demo  | [Github](model_diagnostics/custom_metrics_demo.ipynb) | [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/Labelbox/labelbox-python/blob/develop/examples/model_diagnostics/custom_metrics_demo.ipynb) |