Update README.md

mrkn · mrkn · commit 6fcb046f171f · 2019-06-20T11:35:18.000+09:00
diff --git a/README.md b/README.md
@@ -69,7 +69,7 @@ plot.render($stdout)
 
 ### lineplot
 
-See Usage section above.
+See [Usage](#usage) section above.
 
 ### scatterplot
 
