Include TypeScript Declarations in JS Build

[rajsite]

The JS build only emits a JS file based on the following configuration generated by the DSP:

    "js": {
      "files": [
        {
          "destination": "tokens.js",
          "format": "javascript/es6"
        }
      ],
      "transformGroup": "js",
      "buildPath": "js/"
    },

The default generation scripts should include TypeScript es6 definition files as well. It does not interfere with JS modules and improves TypeScript support:

    "js": {
      "files": [
        {
          "destination": "tokens.js",
          "format": "javascript/es6"
        },
        {
          "destination": "tokens.d.ts",
          "format": "typescript/es6-declarations"
        }
      ],
      "transformGroup": "js",
      "buildPath": "js/"
    },