breaking: support webpack v5

BREAKING CHANGE: Since cypress now bundles with webpack v5, the minimum webpack version is now version 5 as this iswhat cypress will support in the monorepo moving forward. If you wish to use webpack 4, please use v2 of this package.

npm/webpack-batteries-included-preprocessor/README.md

@@ -14,6 +14,8 @@ This preprocessor is a wrapper for [@cypress/webpack-preprocessor](https://githu
 
 Note that installing [@cypress/webpack-preprocessor](https://github.com/cypress-io/cypress-webpack-preprocessor) is also required. This allows you to update its version separately from this wrapper.
 
+For webpack `v5`, use `@cypress/webpack-batteries-included-preprocessor@3.x.x`. For webpack `v4`, use `@cypress/webpack-batteries-included-preprocessor@2.x.x`.
+
 ```sh
 npm install --save-dev @cypress/webpack-batteries-included-preprocessor @cypress/webpack-preprocessor
 ```