docs: specify to use yarn v1 not v2 (#3799)

Co-authored-by: David Luzar <luzar.david@gmail.com>

.gitignore

@@ -5,9 +5,11 @@
 .env.test.local
 .envrc
 .eslintcache
+.history
 .idea
 .vercel
 .vscode
+.yarn
 *.log
 *.tgz
 build

README.md

@@ -93,7 +93,7 @@ These instructions will get you a copy of the project up and running on your loc
 #### Requirements
 
 - [Node.js](https://nodejs.org/en/)
-- [Yarn](https://yarnpkg.com/getting-started/install)
+- [Yarn](https://yarnpkg.com/getting-started/install) (v1 or v2.4.2+)
 - [Git](https://git-scm.com/downloads)
 
 #### Clone the repo