Function install_npm_tool 

pub fn install_npm_tool(
    dev_tools_dir: &Path,
    bin_dir: &Path,
    bin_name: &str,
    npm_name: &str,
    packages: &[&str],
) -> Result<()>

Common install pattern for npm-based tools: download via npm, symlink the binary, and make it executable.

Errors

• If npm download fails.
• If symlink creation fails.
• If chmod fails.