explain files for analysis example notebook

analysis_example/README.md

@@ -1 +1,5 @@
-Example files for use in the analysis notebook.
+Files for the [Analysis examples notebook](https://github.com/murthylab/sleap-notebooks/blob/master/Analysis_examples.ipynb). The predictions were trained on the [Drosophila melanogaster courtship sample dataset](https://github.com/murthylab/sleap-datasets).
+
+The analysis notebook just uses the `predictions.analysis.h5` HDF5 file. If you want to take a look at the predictions in the SLEAP GUI, you can download the other files and open `predictions.slp` using `sleap-label`.
+
+Note that the video here is distinct from the video in the training dataset.