Inject Extensions

Adds

• Supports inject extension (Javascript script) to extend client functionalities, manipulate UI.
  To use extensions, add your desired extension names in config, separated them by | character.
  Example:

[AdditionalOptions]
...
extensions                   = autoSkipExplicit.js|queueAll.js|djMode.js|shuffle+.js|trashbin.js

Extension files can be store in:

• Extensions folder in Home directory:
  Windows: %userprofile%\.spicetify\Extensions\
  Linux: ~/.spicetify/Extensions/
  MacOS: ~/spicetify_data/Extensions
• Extensions folder in Spicetify executable directory.
  If there are 2 extensions having same name, extension in Home directory is prioritized.

Some Spotify API are leaked and put in global object Spicetify. Check out global.d.ts for API documentation.