Webpack 5 release announcement

[srittau]

When I go to webpack.js.org, I get a popup in the lower left corner saying:

Webpack 5 has been officially released. Read our announcement. Not ready yet? Read webpack 4 documentation here.

Considering that Webpack 5 has been released 3.5 years ago, maybe it's time to retire that notice?

[alexander-akait]

Some people still use webpack 4 😞

[srittau]

In that case, maybe reword it a bit? Mentioning the release announcement makes it sound as if this is a fairly recent development. Maybe something along the lines of:

You are reading the documentation for webpack 5, the latest release. Read the webpack 4 documentation here. See the migration guide for upgrading to webpack 5.

[alexander-akait]

@srittau Do you want to send a PR, I am fine with it, thank you