Exporter - get variable descriptions from Figma

[srambach]

Figma allows for entry of a description for each variable (token). We need to pull these into the token file so that the docs framework can consume them for display.

(And Figma will need to have the descriptions added)

Information from @mfrances17:

• The README will explain how to get the plugin installed and working in the Figma library.
• The code to focus on is in code.js, and is written in vanilla javascript but should be rewritten as Typescript
• To debug, import the manifest from a cloned design-tokens repo as instructed in the readme and the changes you make in code.js should be reflected in real time as the plugin is running.
• What i’ve tried and should work is to use figma.variables.getVariableById(value.id).description to pull in the descriptions, but every figma library i’ve tried it on, description is coming back empty or undefined.