Use kramdown's automatic links in 3.1.0 post (en, ja)

Author: stomar

en/news/_posts/2021-12-25-ruby-3-1-0-released.md

@@ -26,9 +26,9 @@ With this technology, YJIT achieves both fast warmup time and performance improv
 
 YJIT is still an experimental feature, and as such, it is disabled by default. If you want to use this, specify the `--yjit` command-line option to enable YJIT. It is also limited to Unix-like x86-64 platforms for now.
 
-* [https://bugs.ruby-lang.org/issues/18229](https://bugs.ruby-lang.org/issues/18229)
-* [https://shopify.engineering/yjit-just-in-time-compiler-cruby](https://shopify.engineering/yjit-just-in-time-compiler-cruby)
-* [https://www.youtube.com/watch?v=PBVLf3yfMs8](https://www.youtube.com/watch?v=PBVLf3yfMs8)
+* <https://bugs.ruby-lang.org/issues/18229>
+* <https://shopify.engineering/yjit-just-in-time-compiler-cruby>
+* <https://www.youtube.com/watch?v=PBVLf3yfMs8>
 
 ## debug gem: A new debugger
 

ja/news/_posts/2021-12-25-ruby-3-1-0-released.md

@@ -26,9 +26,9 @@ MJITがメソッドベースのJITコンパイラであり、外部のCコンパ
 
 YJITはまだ実験的機能なため、デフォルトでは無効化されています。試してみたい場合には `--yjit` コマンドラインオプションを指定することでYJITを有効化出来ます。現在YJITはx86-64上のUnix系プラットフォームでのみ実行出来ます。
 
-* [https://bugs.ruby-lang.org/issues/18229](https://bugs.ruby-lang.org/issues/18229)
-* [https://shopify.engineering/yjit-just-in-time-compiler-cruby](https://shopify.engineering/yjit-just-in-time-compiler-cruby)
-* [https://www.youtube.com/watch?v=PBVLf3yfMs8](https://www.youtube.com/watch?v=PBVLf3yfMs8)
+* <https://bugs.ruby-lang.org/issues/18229>
+* <https://shopify.engineering/yjit-just-in-time-compiler-cruby>
+* <https://www.youtube.com/watch?v=PBVLf3yfMs8>
 
 ## debug gem: 新しいデバッガ