Expand the glob string from the specified root directory and yield each result as a WalkEntry object.

See globToRegExp() for details on supported syntax.

Example:

     import { expandGlob } from "https://deno.land/std@0.223.0/fs/expand_glob.ts";
     for await (const file of expandGlob("**\/*.ts")) {
       console.log(file);
     }