Docs: Fix heading level

docs/setup.en.md

@@ -62,7 +62,7 @@ Well done! Now, you have an environment that run to Misskey.
 ### Launch
 Just `sudo npm start`. GLHF!
 
-#### Way to Update to latest version of your Misskey
+### Way to Update to latest version of your Misskey
 1. `git reset --hard && git pull origin master`
 2. `npm install`
 3. `npm run build`

docs/setup.ja.md

@@ -63,7 +63,7 @@ web-push generate-vapid-keys
 ### 起動
 `sudo npm start`するだけです。GLHF!
 
-#### Misskeyを最新バージョンにアップデートする方法:
+### Misskeyを最新バージョンにアップデートする方法:
 1. `git reset --hard && git pull origin master`
 2. `npm install`
 3. `npm run build`