[SmartCrawl Pro] Auto-Add Sitemap URL to robots.txt WordPress Multisite

For WordPress Subsites on a Multisite installation. It would be nice if, when, the Sitemap function is activated on a subsite, the Sitepmap URL is automatically added to the robots.txt file. Each additional subsite would get its own url added as well.

Example (robots.txt)

Sitemap: https://primarywebsite.com/sitemap.xml

Sitemap: https://subsite01.com/sitemap.xml

Sitemap: https://subsite02.com/sitemap.xml

Sitemap: https://subsite03.com/sitemap.xml

Sitemap: https://subsite04.com/sitemap.xml

Sitemap: https://subsite05.com/sitemap.xml

Sitemap: https://subsite06.com/sitemap.xml

…and so on