Merge pull request #14 from hiroyuki-sato/topic/caution-jruby

Add a link JRuby 9.1.15.0 issue

index.html

@@ -96,7 +96,7 @@ <h3>Windows</h3>
 
       <h3>Set up with JRuby</h3>
       <p>Download your preferred version 9.x.y of JRuby Complete jar from <a href="https://www.jruby.org/download">JRuby Downloads</a>, and put it in your favorite directory.</p>
-      <p>Embulk is tested with old JRuby 9.1.15.0 as of now.</p>
+      <p>Embulk is tested with old JRuby 9.1.15.0 as of now. (However, older JRuby has an <a href="articles/2023/07/28/embulk-gem-install-in-v0_9-series-sometime-fails.html">issue in installing Ruby gems</a>. You may need to try newer JRuby.)</p>
 
 
       <p>Then, create <code>~/.embulk/embulk.properties</code> as follows.</p>