(Vegvisir 3)
vegvisir.Navigation.MODEChange if content should be replaced or inserted when used in .navigate().
REPLACEContent of the destination URL will replace the content at vegvisir.Navigation.POSITION.
INSERTContent of the destination URL will append/prepend to the existing content at vegvisir.Navigation.POSITION.
Setting the mode to INSERT will make .navigate() behave exactly like HTMLElement.insertAdjacentElement().