Readme fixes

This PR fixes two issues with the Readme:
1. Fixes a bug in the `pre_install` block where bundles with spaces in the path could cause files to be deleted inadvertently. The default for `split` is whitespace.
2. I added `base` to the list of allowed locales. This isn't critical, but it works well as an example for the Readme, since certain pods use `base` instead of `en`.