Merge pull request #8 from alexanderthclark/codex/update-data/readme.md-with-csv-details

Add dataset descriptions

Author: alexanderthclark

Data/readme.md

@@ -1 +1,12 @@
-# Data 
+# Data
+
+This folder contains CSV files used in the examples throughout *Matplotlib for Storytellers*. All of the files were downloaded from [Google Trends](https://trends.google.com) and contain normalized search interest values ranging from 0–100. The data is provided here for educational use and remains subject to Google's Terms of Service.
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+## Files
+
+- **AristotleSparkNotesTrends.csv** – Weekly U.S. search interest for "Aristotle" and "SparkNotes" from January 2019 through December 2020.
+- **SparkNotesFall2019.csv** – Daily U.S. search interest for "SparkNotes" covering August–December 2019.
+- **finalFourTrend.csv** – Monthly U.S. search interest for "Final four" from January 2004 through July 2021.
+- **HopperOstromTrends.csv** – Monthly U.S. search interest for "Grace Hopper" and "Elinor Ostrom" from January 2004 through July 2021.
+- **WeatherAug1415Trends.csv** – Minute-level search interest for "weather" collected August 14–15, 2021 (time zone −04:00).
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