Artifact output paths symlinks

## Overview

Explore how we can symlink artifact output paths to locations on the file system to enable system configuration.

## Example

```rust
let symlink = ArtifactSymlink {
  from: format!("{}/config.txt", get_envkey(example)),
  to: "/home/user/.config/example/config.txt"
};

RustBuilder::new("example", systems)
  .with_symlinks(vec![symlink])
  .build(context)?;
```