method Quarrel.prototype.flagimport { Quarrel } from "https://deno.land/x/quarrel@v0.5.0/mod.ts"; flag(shortName: String | string,longName: String | string,description: String | string,options?: flagOptions | Function | null,): voidParametersshortName: String | stringlongName: String | stringdescription: String | stringoptionaloptions: flagOptions | Function | null = [UNSUPPORTED]Returnsvoid