Update quota_check.md to include infra directory step

Added a step to navigate to the 'infra' directory before accessing the 'scripts' folder.

Author: Harmanpreet-Microsoft

docs/quota_check.md

@@ -79,6 +79,7 @@ The final table lists regions with available quota. You can select any of these
    ![git_bash](images/git_bash.png)
 3. Navigate to the `scripts` folder where the script files are located and make the script as executable:
    ```sh
+    cd infra
     cd scripts
     chmod +x quota_check_params.sh
     ```