refactor: organize app extensions

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/extensions/essential-app-extensions/emoji/emoji-app-extension.ts

@@ -0,0 +1,40 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+import type { CheatsheetExtension } from '../../../components/editor-page/cheatsheet/cheatsheet-extension'
+import { regexCompletion } from '../../../components/editor-page/editor-pane/autocompletions/regex-completion'
+import type { MarkdownRendererExtension } from '../../../components/markdown-renderer/extensions/_base-classes/markdown-renderer-extension'
+import { AppExtension } from '../../_base-classes/app-extension'
+import { EmojiMarkdownRendererExtension } from './emoji-markdown-renderer-extension'
+import { emojiShortcodes } from './mapping'
+import type { CompletionSource } from '@codemirror/autocomplete'
+import { t } from 'i18next'
+
+export class EmojiAppExtension extends AppExtension {
+  buildMarkdownRendererExtensions(): MarkdownRendererExtension[] {
+    return [new EmojiMarkdownRendererExtension()]
+  }
+
+  buildCheatsheetExtensions(): CheatsheetExtension[] {
+    return [
+      {
+        i18nKey: 'emoji',
+        readMoreUrl: new URL('https://twemoji.twitter.com/')
+      }
+    ]
+  }
+
+  buildAutocompletion(): CompletionSource[] {
+    return [
+      regexCompletion(
+        /:(?:[\w-+]+:?)?/,
+        emojiShortcodes.map((shortcode) => ({
+          detail: t('editor.autocompletions.emoji') ?? undefined,
+          label: `:${shortcode}:`
+        }))
+      )
+    ]
+  }
+}