• #110: Support for Borg repository initialization via borgmatic --init command-line flag.
• #111: Update Borg create --filter values so a dry run lists files to back up.
• #113: Update README with link to a new/forked Docker image.
• Prevent deprecated --excludes command-line option from being used.
• Refactor README a bit to flow better for first-time users.
• Update README with a few additional borgmatic packages (Debian and Ubuntu).