fix(format): 'typescript/es6-declarations' return type

[Dru89]

This change fixes an issue where all variables exported from 'typescript/es6-declarations' are assumed to be of type string.

Before this, if you had an input type like:

{
  "color": {
    "blue": { "value": "#0000ff" },
  },
  "size": {
    "padding": { "value": 2 }
  }
}

Your output ES6 module would be:

export const ColorBlue = "#0000ff";
export const SizePadding = 2;

But your output TypeScript module would be:

export const ColorBlue : string;
export const SizePadding : string;

This adds some basic type checking for a few known values, and will fall back to any if the type can't be easily determined. It will look for:

• strings
• numbers
• booleans
• or arrays of any of those things

If it can't determine the type, it will fall back to any (or any[] if we know it's an array).

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[dbanksdesign]

LGTM!