Docs: replace the command to install relay/macro (#7262)

soufDev · iansu · commit fc5ee76ae999 · 2019-06-23T13:50:04.000-06:00
diff --git a/docusaurus/docs/adding-relay.md b/docusaurus/docs/adding-relay.md
@@ -14,7 +14,7 @@ npm install --save babel-plugin-relay
 Alternatively you may use `yarn`:
 
 ```sh
-yarn upgrade babel-plugin-relay
+yarn add babel-plugin-relay
 ```
 
 Then, wherever you use the `graphql` template tag, import the macro:
