title: ESLint Typescript not picking up module declarations
body: <p>I'm using <a href="https://www.npmjs.com/package/react-native-dotenv" rel="nofollow noreferrer">https://www.npmjs.com/package/react-native-dotenv</a></p>
  <p>To use that properly, I've got this module declaration:</p>
  <pre><code>declare module '@env' {
    export const SOME_VAR: any;
  }
  </code></pre>
  <p>Imported as follows:</p>
  <pre><code>import { SOME_VAR } from '@env';
  </code></pre>
  <p>ESLint keeps throwing one of these when I import it, though:</p>
  <p><code>ESLint: Unable to resolve path to module '@env'.(import/no-unresolved)</code></p>
  <p>I haven't been able to figure out why. Here's the <code>.eslintrc.js</code></p>
  <pre><code>module.exports = {
    parser: '@typescript-eslint/parser',
    parserOptions: {
      ecmaFeatures: {
        jsx: true,
      },
      ecmaVersion: 2018,
      sourceType: 'module',
      project: 'tsconfig.json',
    },
    plugins: ['react'],
    extends: [
      'airbnb',
      'plugin:@typescript-eslint/recommended',
      'prettier',
      'plugin:prettier/recommended',
      'plugin:import/errors',
      'plugin:import/warnings',
      'plugin:import/typescript',
    ],
    root: true,
    env: {
      browser: true,
      es6: true,
    },
    globals: {
      Atomics: 'readonly',
      SharedArrayBuffer: 'readonly',
    },
    ignorePatterns: ['.eslintrc.js', 'src/generated/*'],
    rules: {
      'prettier/prettier': 'error',
      '@typescript-eslint/explicit-module-boundary-types': 'off',
      'import/extensions': [
        'error',
        'ignorePackages',
        {
          js: 'never',
          jsx: 'never',
          ts: 'never',
          tsx: 'never',
        },
      ],
    },
  };
  
  </code></pre>