🚧 Fix .ts file become Missing file extension error.

cf.
-  import-js/eslint-plugin-import#1573 (comment)
- https://stackoverflow.com/questions/59265981/typescript-eslint-missing-file-extension-ts-import-extensions

.eslintrc.js

@@ -15,7 +15,28 @@ module.exports = {
   parserOptions: {
     project: './tsconfig.json',
   },
+  settings: {
+    'import/extensions': ['.js', '.jsx', '.ts', '.tsx'],
+    'import/parsers': {
+      '@typescript-eslint/parser': ['.ts', '.tsx'],
+    },
+    'import/resolver': {
+      node: {
+        extensions: ['.js', '.jsx', '.ts', '.tsx'],
+      },
+    },
+  },
   rules: {
+    'import/extensions': [
+      'error',
+      'ignorePackages',
+      {
+        js: 'never',
+        jsx: 'never',
+        ts: 'never',
+        tsx: 'never',
+      },
+    ],
     'import/prefer-default-export': 'off',
     'newline-before-return': 'error',
     'no-console': 'warn',