feat: 초기 프로젝트 설정 및 룰.md 파일 추가

api.hyungi.net/node_modules/dayjs/plugin/timezone.d.ts

@@ -0,0 +1,20 @@
+import { PluginFunc, ConfigType } from 'dayjs'
+
+declare const plugin: PluginFunc
+export = plugin
+
+declare module 'dayjs' {
+  interface Dayjs {
+    tz(timezone?: string, keepLocalTime?: boolean): Dayjs
+    offsetName(type?: 'short' | 'long'): string | undefined
+  }
+
+  interface DayjsTimezone {
+    (date?: ConfigType, timezone?: string): Dayjs
+    (date: ConfigType, format: string, timezone?: string): Dayjs
+    guess(): string
+    setDefault(timezone?: string): void
+  }
+
+  const tz: DayjsTimezone
+}