ESP32 minimal httpd_uri_t example (ESP-IDF)

This httpd_uri_t handler just answers Hello World!:

static const httpd_uri_t rootHandler = {
    .uri       = "/",
    .method    = HTTP_GET,
    .handler   = [](httpd_req_t *req) {
        httpd_resp_set_type(req, "text/html");
        httpd_resp_send(req, "<h1>Hello World!</h1>", HTTPD_RESP_USE_STRLEN);

        return ESP_OK;
    }
};