Git Sync, URL Sync & Polish

[six7]

This PR adds functionality for a sync with GitHub and includes a new URL sync option as well as some other improvements.

GitHub sync

Users would have to create a Personal Access Token with scope repo, define their repo, e.g. six7/figma-tokens define a branch they want to work on and a filename/path (e.g. tokens.json)

Then they'd be able to pull from GitHub and push with a custom commit message

Still open:

• Improve experience when opening plugin
• Add dirty state when local changes need to be synced
• Check and refactor JSONBin integration
• Add easy PR creation link
• Enable quick branch switch
• Write tests
• Create CLI tool to transform and resolve token object to something style dictionary can read

Resolves #134
Resolves #271

URL sync

• URL sync option (Add an external URL to sync as a Read Only user. You can also add a JSONBin and access it as a read only user provided you have the credentials) - fixes User roles to avoid editing JSON #251

Other improvements

• Remove Resize Window from Options. You can now drag the bottom right corner of the plugin window to do that.
• You can now exclude tokens from being created as styles by having their names begin with a _, e.g. colors.blue._hue or whole groups by using _global.blue.100 - fixes Enable to exclude tokens from generating styles #264
• Token names that contain a / in it's name are now automatically transformed to names containing . instead. Fixes Allow nesting / grouping of tokens via "/" naming convention #274
• Fixed a bug with colors when displayed in list mode - fixes Make whole token item right-click-target #275
• Fixed a bug with color thumbnails not being displayed correctly - fixes issue with color thumbnails when using reference + alpha? #266
• Fixes Math isn't working inside rgba() function #166
• Fixes Math not properly evaluated #209
• Fixes opacity values sometimes evaluating to 0.52 in Figma
• Adds unique check to token names
• Fixes Error parsing tokens SyntaxError: Unexpected end of JSON input in console #270
• Fixes Support JSON5 import #283
• Fixes Name colors are not converted when creating figma styles #276
• Fixes Allow duplication of tokens #142
• Fixes Something went wrong! Figma Tokens Version 66 #296
• Deep equality check on imported typography styles #292 Adds deep equality check to Style Import to fix typography styles always labelled changed, thanks @tpict