Added clarifying note about which OneCall API is used

README.md

@@ -55,7 +55,7 @@
        - [*"weather"*](https://openweathermap.org/current), the current weather
          data set
        - [*"onecall"*](https://openweathermap.org/api/one-call-api), the "One
-         Call API" data set
+         Call v2.5 API" data set (note: does *not* use the v3.0 API)
        - [*forecast*](https://openweathermap.org/forecast5), the 5-day/3-hour
          forecast data set
        - [*air_pollution*](https://openweathermap.org/api/air-pollution), the air
@@ -152,4 +152,4 @@ The `edu.unl.cse.soft160.json_connections.connector.OpenWeatherConnector` class
 provides a wrapper for `RestConnection` and `FileConnection` to simplify client
 code that uses data from [OpenWeathermap.org](https://openweathermap.org).
 
-**In a typical project, you should only need to directly use `OpenWeatherConnector`.**
\ No newline at end of file
+**In a typical project, you should only need to directly use `OpenWeatherConnector`.**