Customizable internal strings to support i18n #868
Description
What are your thoughts on how we will localize the aria-labels in the viewer? Ex:
https://github.com/GoogleWebComponents/model-viewer/blob/e316b45d8e4eda631f9cbac88e9cf0e3e537bbbe/src/template.ts#L255
I know some of the properties can be done with slots, but for others we'll need to find some way to localize it.