html: update README

diff --git a/html/README.md b/html/README.md
index c3a11fcf517c08e0b9b9052300190c15b1663286..0902433153e954d0defd2b1b93e77295e936470d 100644 (file)
--- a/html/README.md
+++ b/html/README.md
@@ -1,6 +1,8 @@
 ## Prerequisites
 
-install [Yarn](https://yarnpkg.com/getting-started/install), and run: `yarn install`.
+> **NOTE:** yarn v2 is required.
+
+Install [Yarn](https://yarnpkg.com/getting-started/install), and run: `yarn install`.
 
 ## Development