Merging two sitemap.xml files from Docusaurus and Jekyll

Currently, I am using two generating tools: Docusaurus and Jekyll, to generate the website separately. Then I merge those generated files.

I am cautious about making sure every file has its place so that there will be no conflict and overwritten happen when merging them. However, there's one exception those two tools are all generating the sitemap.xml files.

I want to rename them to other names like sitemap.docusaurus.xml and sitemap.jekyll.xml, then create a new sitemap.xml to include them all.