Adding react and react-dom as dependencies for Yarn PnP (#525)

* Adding `react` and `react-dom` as dependencies for Yarn PnP

Yarn V2 refuses access to packages which are not listed as a dependency. This should help fix it.

Details: https://yarnpkg.com/advanced/rulebook#packages-should-only-ever-require-what-they-formally-list-in-their-dependencies

* Update package.json

* Widen react peerDependency range

Co-authored-by: Samuel Reed <samuel.trace.reed@gmail.com>

Author: cozimacode

package.json

@@ -90,5 +90,9 @@
   "dependencies": {
     "classnames": "^2.2.5",
     "prop-types": "^15.6.0"
+  },
+  "peerDependencies": {
+    "react": ">= 16.3.0",
+    "react-dom": ">= 16.3.0"
   }
-}
+}