Update README.md

README.md

@@ -1,12 +1,23 @@
-# WIP
+# Polars-business
 
-Just sharing this try debugging something
+![DALL·E 2023-10-11 16 02 10 - polar bear in business suit](https://github.com/MarcoGorelli/polars-business-day-tools/assets/33491632/46575111-4d14-452b-ac98-548acab3cf8f)
 
-Steps to reproduce:
+Business day utilities for [Polars](https://www.pola.rs/).
 
-1. make venv: `python3.11 -m venv .venv`
-2. `.venv/bin/activate`
-3. `pip install maturin polars`
-4. `cd src`
-5. `maturin develop -m polars_business_day_tools/Cargo.toml `
-6. `python run.py`
+Install with `pip install polars-business-day-tools`.
+
+Example
+-------
+
+Here's an example of how to shift a date range forwards by 5 business days (i.e. Monday to Friday, excluding weekends):
+```python
+import polars as pl
+from polars_business_day_tools import BusinessDayTools
+from datetime import date
+
+df = pl.DataFrame({
+    "dates": pl.date_range(date(2000, 1, 1), date(9999, 1, 1), eager=True),
+})
+
+print(df.with_columns(dates_shifted=pl.col('dates').bdt.advance_by_days(n=5)))
+```