Update v0.11.2 to v0.11.4

Author: hiroyuki-sato

_config.yml

@@ -4,6 +4,7 @@
 # You can create any custom variable you would like, and they will be accessible
 # in the templates via {{ site.myvariable }}.
 title: Embulk
+embulk_version: 0.11.4
 # email: your-email@example.com
 # description: >- # this means to ignore newlines until "baseurl:"
 #   Write an awesome description for your new site here. You can edit this

index.html

@@ -32,7 +32,7 @@
       <h2>Latest Versions</h2>
       <dl>
         <dt>Stable</dt>
-        <dd><a href="https://github.com/embulk/embulk/releases/tag/v0.11.2">v0.11.2</a></dd>
+        <dd><a href="https://github.com/embulk/embulk/releases/tag/v{{ site.embulk_version }}">v{{ site.embulk_version }}</a></dd>
         <dd>Note that v0.11 is not fully compatible with v0.9. Several plugins for v0.9 would not work with v0.11.</dd>
         <dd>Take a look at <a href="{{ "articles/2023/04/13/embulk-v0.11-is-coming-soon.html" | relative_url }}">this article</a> for details.</dd>
         <dt>Past stable</dt>
@@ -104,7 +104,7 @@ <h3>Set up with JRuby</h3>
 
       <p>Finally, install some Ruby gems.</p>
 
-      <pre><code>embulk gem install embulk -v 0.11.2 # Must be the same Embulk version
+      <pre><code>embulk gem install embulk -v {{ site.embulk_version }} # Must be the same Embulk version
 embulk gem install msgpack
 embulk gem install bundler # if you need Bundler
 embulk gem install liquid  # if you need Liquid</code></pre>