NewConfig returns a new config.

Config is the source config.

CratesConfig is the crates.io API configuration.

DartFlutterConfig is the dart and flutter configuration.

GitHubConfig is the GitHub configuration.

GoProxyConfig is the go proxy configuration.

MavenConfig is the maven search configuration.

NPMRegistryConfig is the npm registry configuration.

Source is the configuration for the fetch source.

Cacheable indicates that a given config can be cached by the returned key.