Fix the error message to be a bit more specific, as to why the CredentialStoreItem could not be added.

src/Item/New-CredentialStoreItem.ps1

@@ -84,7 +84,7 @@ function New-CredentialStoreItem {
         if (-not(Test-CredentialStore -Shared -Path $Path)) {
             $MessageParams = @{
                 Exception   = [System.IO.FileNotFoundException]::new(
-                    'Could not add anything into the given CredentialStore.'
+                    'The given credential store ({0}) does not exist!' -f $Path
                 )
                 ErrorAction = "Stop"
             }