Add custom site path

Hi,

Your plugin saved myn project.
Since i have a headless setup with my frontend on a different location:
One improvement would be to actually go further then ‘relative’

I add a constant to ‘class-make-relative.php’ on line 123
$relative_link = FRONTEND_URL.$link;

And replace FRONTEND_URl with my fronted url

Now I can access my posts and internal links (within the content editor) at all times

I was first thinking of changing the site_path, but this breaks the wp-json, and my wordpress theme which contain custom rest controllers