better sluggyfier

[vincent-peugnet]

Currently W's accent remove for ID is very homemade. I just did some basic french-used-accent replacement.

I could use a better function, for exemple the one used by Wordpress :

https://github.com/WordPress/wordpress-develop/blob/87dfd5514b52aef456b7232b1959873e69e651da/src/wp-includes/formatting.php#L1607-L2013

https://developer.wordpress.org/reference/functions/remove_accents/