OGP向けにインスタンスのバナー画像を提供するように

src/server/web/views/base.pug

@@ -0,0 +1,44 @@
+block vars
+
+doctype html
+
+!= '\n<!-- Thank you for using Misskey! @syuilo -->\n'
+
+html
+
+	head
+		meta(charset='utf-8')
+		meta(name='application-name' content='Misskey')
+		meta(name='referrer' content='origin')
+		meta(property='og:site_name' content='Misskey')
+		link(rel='manifest' href='/manifest.json')
+
+		title
+			block title
+				| Misskey
+
+		block desc
+			meta(name='description' content='A planet of fediverse')
+
+		block meta
+
+		block og
+			meta(property='og:image' content=img)
+
+		style
+			include ./../../../../built/client/assets/init.css
+		script
+			include ./../../../../built/client/assets/boot.js
+
+		script
+			include ./../../../../built/client/assets/safe.js
+
+	body
+		noscript: p
+			| JavaScriptを有効にしてください
+			br
+			| Please turn on your JavaScript
+		div#ini.
+			<svg viewBox="0 0 50 50">
+				<path fill=#fb4e4e d="M25.251,6.461c-10.318,0-18.683,8.365-18.683,18.683h4.068c0-8.071,6.543-14.615,14.615-14.615V6.461z" />
+			</svg>