Fix path literal in motd for windows path strings

config/nushell/motd.nu.tmpl

@@ -6,7 +6,7 @@ Did you know: (ansi purple_bold)(fact)(ansi reset)"
 }
 
 def fact [] {
-  let cache_file = "{{dirs.data}}/facts.txt"
+  let cache_file = '{{dirs.data}}' | path join facts.txt
   if not ($cache_file | path exists) {
     touch $cache_file
   }