Update README

Author: takezoe

README.md

@@ -21,7 +21,7 @@ Plugin version|GitBucket version
 Download
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-You can download the JAR file from the [Release](https://github.com/gitbucket-plugins/gitbucket-explorer-plugin/releases).
+You can download the JAR file from the [plugin registry](https://plugins.gitbucket-community.org/releases/gitbucket-explorer-plugin).
 
 Installation
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