finish example thanks to fdncred

Pure gold: https://github.com/nushell/nu_scripts/pull/104#issuecomment-956335793

ls_mods/ls-hidden.nu

@@ -1 +1,6 @@
-ls -a | where | { each { echo $it.name | str starts-with '.'} }
+
+def ls-hidden [
+    --dir(-d):any # The directory you want to list
+] {
+	ls -a $dir | where { ($it.name | into string | str starts-with '.') }
+}