docs: fix typos in d/users.html.markdown (#1049)

data.github_user -> data.github_users

Co-authored-by: Keegan Campbell <[email protected]>

Author: pallxk

website/docs/d/users.html.markdown

@@ -18,11 +18,11 @@ data "github_users" "example" {
 }
 
 output "valid_users" {
-  value = "${data.github_user.example.logins}"
+  value = "${data.github_users.example.logins}"
 }
 
 output "invalid_users" {
-  value = "${data.github_user.example.unknown_logins}"
+  value = "${data.github_users.example.unknown_logins}"
 }
 ```