Applying and starting storyboards - eventtrigger not the only trigger for xaml

[Applying and Starting Storyboards](https://github.com/dotnet/docs/blob/live/docs/framework/wpf/graphics-multimedia/animation-overview.md#applying-and-starting-storyboards)

> To start a storyboard in XAML, you associate it with an EventTrigger

Although this was preceded with

> The sections that follow provide an **example** of naming an element in XAML and code. For more detailed information about naming and targeting, see the Storyboards Overview.

It should state "To start a storyboard in XAML, you **can** associate it with an EventTrigger". It would be advisable to link to [How to Apply Animations with a Storyboard](https://github.com/dotnet/docs/blob/live/docs/framework/wpf/graphics-multimedia/storyboards-overview.md#how-to-apply-animations-with-a-storyboard) - for further details...