Add polars versus pandas performance benchmarks

Author: gjbex

source-code/polars/README.md

@@ -14,4 +14,6 @@ Polars is an alternative to pandas that is designed to have better performance.
    for benchmarking.
 1. `create_csv_data.slurm`: Slurm script to run `create_csv_data.py` on a
    cluster.
+1. `polars_performance.ipynb`: Jupyter notebook that compares the performance
+   of polars and pandas on a variety of operations.
 1. `data`: Directory containing the data used in the notebook.