Finish up embed modal feature (#4759)

* Add embed button to dropdowns of in-timeline statuses

* yarn run manage:translations

app/javascript/mastodon/locales/ja.json

@@ -63,6 +63,8 @@
   "confirmations.mute.message": "本当に{name}をミュートしますか？",
   "confirmations.unfollow.confirm": "フォロー解除",
   "confirmations.unfollow.message": "本当に{name}をフォロー解除しますか？",
+  "embed.instructions": "Embed this status on your website by copying the code below.",
+  "embed.preview": "Here is what it will look like:",
   "emoji_button.activity": "活動",
   "emoji_button.flags": "国旗",
   "emoji_button.food": "食べ物",
@@ -162,6 +164,7 @@
   "standalone.public_title": "今こんな話をしています",
   "status.cannot_reblog": "この投稿はブーストできません",
   "status.delete": "削除",
+  "status.embed": "Embed",
   "status.favourite": "お気に入り",
   "status.load_more": "もっと見る",
   "status.media_hidden": "非表示のメディア",