this script can pull multiple rss feeds and show them in one feed.
I have this running here if you want to take a look at it live. https://weboasis.digital/news/
Scroll down to the code where it says Define the RSS feeds to be read and right under that you will see the two current feeds. just do {url: "https://thewebsitethatyouwillbepullingitsfeedfrom.com/feed", title: "thefeed you are pulling"}
right under the last feed to add a new one.