Expose V's install dir and examples via ENV vars

[larpon]

As the title states it would be nice to be able to get info about where these locations are from the shell.

For me it'd be nice to have them when testing vab against the official examples.

[Ulises Jeremias]

@larpon setup-v now has output! check the doc here!

[larpon]

Perfect! Thanks @ulises-jeremias !