adds note about the breaking change using interaction

docs/guide/migrationV2.md

@@ -9,3 +9,9 @@ A number of changes were made to the configuration options passed to the plugin
  * `xScaleID` option default has been changed, now set to `undefined`. If the option is missing, the plugin will try to use the first scale of the chart, configured as `'x'` axis. If more than one scale has been defined in the chart as `'x'` axis, the option is mandatory to select the right scale.
  * `yScaleID` option default has been changed, now set to `undefined`. If the option is missing, the plugin will try to use the first scale of the chart, configured as `'y'` axis. If more than one scale has been defined in the chart as `'y'` axis, the option is mandatory to select the right scale.
 * When [stacked scales](https://www.chartjs.org/docs/latest/axes/cartesian/#common-options-to-all-cartesian-axes) are used, instead of the whole chart area, the designated scale area is used as fallback for `xMin`, `xMax`, `yMin`, `yMax`, `xValue` or `yValue` options.
+
+## Events
+
+`chartjs-plugin-annotation` plugin version 2 introduces the `interaction` options, to configure which events trigger annotation interactions. By default, the plugin uses the [chart interaction configuration](https://www.chartjs.org/docs/latest/configuration/interactions.html#interactions).
+
+ * When [scatter charts](https://www.chartjs.org/docs/latest/charts/scatter.html) are used, the interaction default `mode` in Chart.js is `point`, while, in the previous plugin version, the default was `nearest`.