public static String extension(String name) {
		int p = name.lastIndexOf('.');
		return p > 0 ? name.substring(p + 1) : "";
	}
Returns the extension of the given file name. The extension will not include
the dot as part of the result. Returns an empty string if the name has no
extension.

@param name A file name
@return An extension or an empty string
src/main/java/dev/jbang/util/Util.java