Fixed code example type

yhunko · web-flow · commit 4dcfc7c0a59a · 2021-03-26T15:44:50.000+02:00
`yarn add` command had two `-D` flags
diff --git a/README.md b/README.md
@@ -12,7 +12,7 @@ First, install plugin.
 ```bash
 npm i vuepress-plugin-fulltext-search -D
 # or
-yarn add -D vuepress-plugin-fulltext-search -D
+yarn add vuepress-plugin-fulltext-search -D
 ```
 
 Then, enable the plugin in your `docs/.vuepress/config.js`:
