docs: update after and onError

Close #995
Reason: 4dc1f1b

Author: posva

packages/docs/core-concepts/actions.md

@@ -120,7 +120,7 @@ export default {
 
 ## Subscribing to actions
 
-It is possible to observe actions and their outcome with `store.$onAction()`. The callback passed to it is executed before the action itself. `after` handle promises and allows you to change the returned value of the action. `onError` allows you to stop the error from propagating. These are useful for tracking errors at runtime, similar to [this tip in the Vue docs](https://v3.vuejs.org/guide/tooling/deployment.html#tracking-runtime-errors).
+It is possible to observe actions and their outcome with `store.$onAction()`. The callback passed to it is executed before the action itself. `after` handle promises and allows you to execute a function after the action resolves. In a similar way, `onError` allows you execute a function if the action throws or rejects. These are useful for tracking errors at runtime, similar to [this tip in the Vue docs](https://v3.vuejs.org/guide/tooling/deployment.html#tracking-runtime-errors).
 
 Here is an example that logs before running actions and after they resolve/reject.