Post final QA fixes

Author: bzaczynski

polars-groupby/README.md

@@ -1,14 +1,27 @@
-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/).
+# How to Group Data Using Polars `.group_by()`
 
-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.
+This download contains materials for the Real Python tutorial [How to Group Data Using Polars `.group_by()`](https://realpython.com/polars-groupby/).
 
-Your download bundle contains the following files:
+## Installation
+
+Create a [Python virtual environment](https://realpython.com/python-virtual-environments-a-primer/), activate it, and install Polars along with its dependencies into it:
+
+```sh
+$ python -m venv venv/
+$ source venv/bin/activate
+(venv) $ python -m pip install polars
+```
 
-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 three files above.
-math_classes.parquet     - This file contains data used in the time series analysis examples.
+## Contents
+
+Your download bundle contains the following files:
 
-tutorial_code.ipynb      - This file contains the code used in the tutorial.
-solutions.ipynb          - This file contains the solutions to the exercises.
+| Filename                  | Description                                                   |
+|------------------------   |------------------------------------------------------------   |
+| `course.parquet`          | All data from both `math.parquet` and `portuguese.parquet`    |
+| `math.parquet`            | Data relating to a mathematics class                          |
+| `portuguese.parquet`      | Data relating to a Portuguese language class                  |
+| `student.txt`             | Defines every field in the three files above                  |
+| `math_classes.parquet`    | Data used in the time series analysis examples                |
+| `tutorial_code.ipynb`     | The code used in the tutorial                                 |
+| `solutions.ipynb`         | The solutions to the exercises                                |