Broken links in System.CommandLine.DragonFruit doc

[jozkee]

#1766 removed some markdown files, which are still being referenced in other documentation files within the repo:

command-line-api/docs/Your-first-app-with-System-CommandLine-DragonFruit.md

Line 62 in c776cd4

This program is equivalent to the one demonstrated in [Your first app with System.CommandLine](Your-first-app-with-System-CommandLine.md).

command-line-api/docs/Your-first-app-with-System-CommandLine-DragonFruit.md

Line 64 in c776cd4

To explore its features, take a look at [Features: overview](Features-overview.md)

There may be more, I didn't check.