fix: add better warning when defaultDateType is not set due to upgrade

quartz/components/Date.tsx

@@ -8,6 +8,9 @@ interface Props {
 export type ValidDateType = keyof Required<QuartzPluginData>["dates"]
 
 export function getDate(cfg: GlobalConfiguration, data: QuartzPluginData): Date | undefined {
+  if (!cfg.defaultDateType) {
+    throw new Error(`Field 'defaultDateType' was not set in the configuration object of quartz.config.ts. See https://quartz.jzhao.xyz/configuration#general-configuration for more details.`)
+  }
   return data.dates?.[cfg.defaultDateType]
 }