fix readme typo

README.md

@@ -13,7 +13,7 @@ A curated directory of high-quality plugins for Claude Code.
 
 Plugins can be installed directly from this marketplace via Claude Code's plugin system.
 
-To install, run `/plugin install {plugin-name}@claude-plugin-directory`
+To install, run `/plugin install {plugin-name}@claude-plugins-official`
 
 or browse for the plugin in `/plugin > Discover`