refactor: covert index, main to TypeScript

Author: gingerbeerlime

src/components/index.js renamed to src/components/index.ts

@@ -0,0 +1,3 @@
+export { default as defaultProps } from './defaultProps'
+export { redColorScaleGenerator } from './redColorScaleGenerator'
+export * from './utilities'

src/composables/index.js renamed to src/composables/index.ts

@@ -1,8 +1,8 @@
 import { VuePivottable, VuePivottableUi } from './components'
 import TableRenderer from './components/pivottable/renderer'
 import * as PivotUtilities from './helper'
-export * from './composables/index.js'
 import type { Component } from 'vue'
+export * from './composables'
 
 const Renderer: Record<string, Component> = {
   ...TableRenderer