Update using-github-classroom-with-github-cli.md

Added missing --page flag for cloning student's repos.
Added an example with --page and --per-page

Author: marcel-suter-bzz

Diff for: content/education/manage-coursework-with-github-classroom/teach-with-github-classroom/using-github-classroom-with-github-cli.md

@@ -104,4 +104,8 @@ gh classroom clone student-repos
 
 Clones student repositories from a given assignment. By default, the student repositories are cloned into the current directory a directory named after the assignment slug. To clone into a different directory, use the `--directory` flag. If the directory does not exists, it will be created.
 
-By default, all student repositories are cloned. To get a different number of repositories, use the `--per-page NUMBER` flag.
+By default, all student repositories are cloned. To get a different number of repositories, use the `--page NUMBER` and `--per-page NUMBER` flags.
+
+```shell
+gh classroom clone student-repos --page 1 --per-page 20
+```