Update README.md

Author: brendaweles

polars-groupby/README.md

@@ -1,4 +1,4 @@
-This download contains materials designed to complement the RealPython tutorial [Aggregating and Grouping Data in Polars](https://realpython.com/aggregating-and-grouping-data-in-polars-groupby/).
+This download contains materials for the Real Python tutorial [How to Group Data Using Polars .group_by()](https://realpython.com/aggregating-and-grouping-data-in-polars-groupby/).
 
 You should create a new folder named aggregations on your computer and place each of these files inside it. You may also consider creating a [Python virtual environment](https://realpython.com/python-virtual-environments-a-primer/) within this folder.
 
@@ -7,7 +7,7 @@ Your download bundle contains the following files:
 course.parquet           - This file contains all data from both `math.parquet` and `portuguese.parquet`.
 math.parquet             - This file contains data relating to a mathematics class.
 portuguese.parquet       - This file contains data relating to a Portuguese language class.
-student.txt              - This file defines every field in the above three files.
+student.txt              - This file defines every field in the three files above.
 math_classes.parquet     - This file contains data used in the time series analysis examples.
 
 tutorial_code.ipynb      - This file contains the code used in the tutorial.