message: Fix typo in shivammathur/node tags in README
diff: @@ -627,13 +627,13 @@ Choose the image tag which matches the `runs-on` property in your workflow. For
  act -P ubuntu-latest=shivammathur/node:latest
  # For runs-on: ubuntu-20.04
  -act -P ubuntu-20.04=shivammathur/node:20.04
  +act -P ubuntu-20.04=shivammathur/node:2004
  # For runs-on: ubuntu-18.04
  -act -P ubuntu-18.04=shivammathur/node:18.04
  +act -P ubuntu-18.04=shivammathur/node:1804
  # For runs-on: ubuntu-16.04
  -act -P ubuntu-16.04=shivammathur/node:16.04
  +act -P ubuntu-16.04=shivammathur/node:1604
  ```
  ### JIT Configuration
  