Installs Chrome for Testing and chromedriver.
Uses npx @puppeteer/browsers install to download matched versions of
Chrome and chromedriver into .browsers/. Writes the executable paths
to .browsers/PATHS so Wallabidi.BrowserPaths can find them.
Usage
mix wallabidi.install # latest stable
mix wallabidi.install 147.0.7727 # specific versionRequirements
Requires npx (Node.js) to be installed. The downloaded binaries are
cached — subsequent runs are fast.