Fix example (denoland#4076)

std/examples/README.md

@@ -40,7 +40,7 @@ echo example.json | catj -
 ### curl - print the contents of a url to standard output
 
 ```shell
-deno --allow-net=deno.land https://deno.land/std/examples/curl.ts -- https://deno.land/
+deno --allow-net=deno.land https://deno.land/std/examples/curl.ts https://deno.land/
 ```
 
 ### gist - easily create and upload Gists