Update dataset community suggestion note

README.md

@@ -28,6 +28,12 @@ The maintainer may stop updating this free dataset at a later, unspecified date.
 
 Existing public files may remain available, but continued free updates are not guaranteed.
 
+## Community Data Suggestions
+
+Learners and researchers may suggest additional ETF fields, derived columns, or documentation improvements for future versions of this dataset. Suggestions are welcome, but there is no guarantee that a requested field will be added.
+
+Requests will be considered based on educational value, licensing and redistribution limits, privacy, data quality, maintainability, and whether the field fits the cleaned teaching-data scope. Raw provider responses, account-specific information, balances, holdings, transactions, orders, and API credentials will not be published.
+
 ## Files
 
 - `etf_daily_prices.parquet`: canonical daily ETF price and volume table.