Extensionless URLs do not end with a trailing slash or a file extension. They map to the file in the same path with an
xml extension. For example, these URLs would serve the same file:
To serve files on extensionless URLs:
Serve Extensionless URLs is on by default for new sites for compatibility with the latest Jekyll versions.
Enabling Force Extensionless URLs redirects URLs with
xml extensions to extensionless versions. This ensures a single URL rather than serving the same file on two different URLs.