Function decamelize

docs/app/js/sanddance-app.js:6645–6647

* Decamelizes a string with/without a custom separator (hyphen by default). * from: https://ourcodeworld.com/articles/read/608/how-to-camelize-and-decamelize-strings-in-javascript * * @param str String in camelcase * @param separator Separator for the new decamelized string.

(str, separator = "-")

 * @param str String in camelcase
 * @param separator Separator for the new decamelized string.
 */ function decamelize(str, separator = "-") {
    return str.replace(/([a-z\d])([A-Z])/g, "$1" + separator + "$2").replace(/([A-Z]+)([A-Z][a-z\d]+)/g, "$1" + separator + "$2").toLowerCase();
}
function createElement(tag, attrs, ...children) {
    if (typeof tag === "function") {
        const fn = tag;