Add multi-file-upload Vue example

[olizilla]

We have multi-file-upload for the other UI libraries but not vue

[travis]

Agree with the idea behind this - having consistent examples across different UI libraries - but I chatted with @yusefnapora yesterday and we're inclined to move away from these usecase-specific examples in favor of more monolithic examples for each level of abstraction (ie, we might want to move to just having a w3console-lite example that demonstrates the CustomizableUI components and a "more custom" example app that demonstrates the HeadlessUI components).

Definitely down to leave this open for now, but I wouldn't recommend spending too much time on it until we cohere around a strategy for examples in this repo at a higher level

[olizilla]

Ah, ok yes. I agree!

[travis]

opened #256 to discuss