Add Babel and Jest configs

babel.config.js

+module.exports = {
+  presets: [
+    ['babel-preset-shopify/node', {typescript: true}]
+  ],
+  sourceMaps: 'inline',
+};

jest.config.js

+module.exports = {
+  moduleFileExtensions: ['ts', 'js', 'json'],
+  transform: {
+    '^.+\\.[t|j]sx?$': 'babel-jest',
+  },
+  watchPathIgnorePatterns: [
+    '<rootDir>/node_modules/',
+  ],
+  testRegex: '.*\\.test\\.tsx?$',
+  coverageDirectory: './coverage/',
+  collectCoverage: true,
+};