Add the ability to display an error page (similar to 404.php)
When there is an error in my custom theme, the theme stops rendering and therefore displays the page with the faulty design, but visitors don't know that it's caused by the error. For example, if I use the <a href="/en/”NO NUMERIC NOISE KEY/" 1000”>If the page is not rendered, it will only display the page background, as it will stop rendering any other page content. This code is for example purposes only and it will cause PHP fatal errors: uncaught type error: array_merge(): parameter #1 must be of type array, given string. Of course, there are no such simple errors in my code, but it is impossible to avoid all fatal errors. I'd like to have the option to show the user the error that occurs in that case, not just to stop rendering the theme. Ideally, a nice separate page would be displayed in the theme, similar to 404.php.
