Initial release

Frontend:

• Use Bulma.io as a frontend framework.
• Select a folder on the system where project is running, from web UI (still needs static base path in config)
• Take asin input after selecting folder

Core:

• Choose mode based off number of input files (merge multiple together, or modify metadata in-place)
• Standardize chapters (will always format chapters like Chapter 01, Chapter 02 ...
• Merge multiple files into one m4b, with metadata from Audible, or if one file, modify existing tags.
• Setup DB models for Author/Narrator/Genre, for future cross-referencing.

API:

• Do basic Audible auth from browser
• Take & validate ASIN input from user in web ui
• Show metadata to user after merge