Single-click playground link

This is a pie-in-the-sky level idea, but in an ideal world, I'd love to be able to select a file / some subset of a file, then click _something_ and get a link to the piece of code selected (or the whole file) on the playground.

## Example

Let's say I have some repro I want to share:
```effekt
import foo

def main() = {
val n: Int = foo::frobnicate(42, 1) // compile error
}
```

I press Ctrl+A to highlight it, then press Ctrl+Shift+P, select "effekt: selection to playground link", and get the following link in my clipboard:
```
https://effekt-lang.org/playground.html?playground=DcpBCoAgEAXQvaf4S4VAilZCB%2BgYZgoDOiODtInuntvHo9ZFB4qIMXcuaJHYOhx4DfDECg44eUyYJYSicjGlOLLdtwWrg%2FdI0jrVjKwqar4f&repl=CmhlbGxvV29ybGQoKQo%3D
```