Implement ref example

[klarkc]

As a proof of concept, let's try to foreign import vue ref function and use it inside purescript code that exports a setup hook.

Something like this:

main.purs

```purs {- main.purs -} module Main where import Prelude import PureVue (Ref, ref) setup = { message: ref "Hello world" } ```

index.js

```js // index.js import { setup } from 'main.purs'; // if not possible: import { setup } from 'main.js'; createApp({ component: { template: "

{{message}}

", setup } }).mount('#app'); ```

Blocked by purescript/purescript#3791

[klarkc]

Related #1

[klarkc]

Probably a better approach using createApp:

main.purs

```purs {- main.purs -} module Main where import Prelude import PureVue (ref, createApp) main :: Effect Unit main = void $ createApp { el: "#app". , template: "

{{message}}

" , setup: \_ -> { message: ref "Hello world" } } ```

index.html

```html

```

[klarkc]

We decided to go with https://github.com/klarkc/pure-vue/issues/1