Enhance(frontend): MFMや絵文字が使える入力ボックスでオートコンプリートを使えるように (#12643)

* rich autocomplete for use in profiles, announcements, and channel descriptions

* implementation omissions

* add tab, apply to page editor, and fix something

* componentization

* fix nyaize doesn't working in profile preview

* detach autocomplete instance when unmounted

* fix: mismatched camelCase

* remove unused / unnecessary styles

* update CHANGELOG.md

* fix lint

* remove dump.rdb

* props.richAutocomplete -> autocomplete

* Update packages/frontend/src/scripts/autocomplete.ts

* clarify namings
メンションなども「MFM」に含まれるのか自信がなかったのでrichSyntaxなどとぼかしていましたが、含むようなので変更しました

* tweak

* Update MkFormDialog.vue

* rename

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>

packages/frontend/src/pages/channel-editor.vue

@@ -12,7 +12,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<template #label>{{ i18n.ts.name }}</template>
 			</MkInput>
 
-			<MkTextarea v-model="description">
+			<MkTextarea v-model="description" mfmAutocomplete :mfmPreview="true">
 				<template #label>{{ i18n.ts.description }}</template>
 			</MkTextarea>
 
@@ -70,7 +70,6 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { computed, ref, watch, defineAsyncComponent } from 'vue';
-import MkTextarea from '@/components/MkTextarea.vue';
 import MkButton from '@/components/MkButton.vue';
 import MkInput from '@/components/MkInput.vue';
 import MkColorInput from '@/components/MkColorInput.vue';
@@ -81,6 +80,7 @@ import { definePageMetadata } from '@/scripts/page-metadata.js';
 import { i18n } from '@/i18n.js';
 import MkFolder from '@/components/MkFolder.vue';
 import MkSwitch from '@/components/MkSwitch.vue';
+import MkTextarea from '@/components/MkTextarea.vue';
 
 const Sortable = defineAsyncComponent(() => import('vuedraggable').then(x => x.default));