fix: refactor codes

Author: kazupon

packages/vue-i18n-core/src/i18n.ts

@@ -60,25 +60,6 @@ import type {
 } from './legacy'
 import type { Disposer } from './types'
 
-declare module 'vue' {
-  // eslint-disable-next-line
-  interface App<HostElement = any> {
-    __VUE_I18N__?: I18n & I18nInternal
-    __VUE_I18N_SYMBOL__?: InjectionKey<I18n> | string
-  }
-}
-
-// internal Component Instance API isCE
-declare module 'vue' {
-  export interface ComponentInternalInstance {
-    /**
-     * @internal
-     * is custom element?
-     */
-    isCE?: boolean
-  }
-}
-
 /**
  * I18n Options for `createI18n`
  *

packages/vue-i18n-core/src/misc.ts

@@ -12,9 +12,9 @@ export const VERSION: string = __VERSION__
 
 /**
  * This is only called in esm-bundler builds.
- * istanbul-ignore-next
+ * @description **Don't use this function in your application code.**
  *
- * @internal
+ * istanbul-ignore-next
  */
 export function initFeatureFlags(): void {
   if (typeof __FEATURE_FULL_INSTALL__ !== 'boolean') {
@@ -36,9 +36,9 @@ export function initFeatureFlags(): void {
 
 /**
  * This is only called development env
- * istanbul-ignore-next
+ * @description **Don't use this function in your application code.**
  *
- * @internal
+ * istanbul-ignore-next
  */
 export function initDev(): void {
   if (__BROWSER__) {

packages/vue-i18n-core/src/vue.d.ts

@@ -0,0 +1,21 @@
+import type { InjectionKey } from 'vue'
+import type { I18n, I18nInternal } from './i18n'
+
+declare module 'vue' {
+  // eslint-disable-next-line
+  export interface App<HostElement = any> {
+    __VUE_I18N__?: I18n & I18nInternal
+    __VUE_I18N_SYMBOL__?: InjectionKey<I18n> | string
+  }
+}
+
+// internal Component Instance API isCE
+declare module 'vue' {
+  export interface ComponentInternalInstance {
+    /**
+     * @internal
+     * iskk custom element?
+     */
+    isCE?: boolean
+  }
+}