v1.0.0-beta.4

• Add the container key to the scaffolded config file when generated with --full (#792)
• Fixes an issue where the user's config object was being mutated during processing (only affects @bradlc 😅)
• Fixes an issue where you couldn't use a closure to define theme sections under extend (#803)
• Removes SFMono-Regular from the beginning of the default monospace font stack, it has no italic support and Menlo looks better anyways (#805)
• Bumps node dependency to 8.9.0 so we can keep our default config file clean, 6.9.0 is EOL next month anyways