Add WASI support

[saghul]

[saghul]

@bnoordhuis Can you PTAL?

[bnoordhuis]

Forgot to say: rad shell prompt! Here's what mine looks like:

$

[saghul]

Forgot to say: rad shell prompt! Here's what mine looks like:

$

hahaha written in rust no less! https://starship.rs/

[chqrlie]

Forgot to say: rad shell prompt! Here's what mine looks like:

$

With or without a trailing space?

[bnoordhuis]

I admit I'm not enough of a purist to forgo that extra blank :)

[dimisus]

Awesome!