message: Update MacOS installation instructions.
  Homebrew/homebrew-cask#55358 changed the name used for installation.
diff: @@ -120,13 +120,13 @@ so it might not refer to the latest version immediately after an Etcher
  release.
  ```sh
  -brew cask install etcher
  +brew cask install balenaetcher
  ```
  ##### Uninstall
  ```sh
  -brew cask uninstall etcher
  +brew cask uninstall balenaetcher
  ```
  #### Chocolatey (Windows)
  