feat(analytics): use Scarf.js to provide anonymized installation analytics

[char0n]

Anonymized analytics

SwaggerUI uses Scarf to collect anonymized installation analytics. These analytics help support the maintainers of this library and ONLY run during installation. To opt out, you can set the scarfSettings.enabled field to false in your project's package.json:

// package.json
{
  // ...
  "scarfSettings": {
    "enabled": false
  }
  // ...
}

Alternatively, you can set the environment variable SCARF_ANALYTICS to false as part of the environment that installs your npm packages, e.g., SCARF_ANALYTICS=false npm install.

[ponelat]

lgtm