content: IonicSafeString does not have a Vue example

[aparajita]

URL

https://ionicframework.com/docs/techniques/security#usage

Issue Description

For IonicSafeString to work correctly with Vue, it has to be imported from @ionic/vue, not @ionic/core. In the absence of an example we are not sure where to import from, specially since it is exported from both packages.

Please add a Vue example.