message: README fix typo
diff: #### Remult :heart: Code Sharing
  -With model types shared between frontend and backend code, Remult can **enforce data validation and constraints, defined once, both in the front-end and witin back-end API routes**.
  +With model types shared between frontend and backend code, Remult can **enforce data validation and constraints, defined once, both in the front-end and within back-end API routes**.
  ## Getting started
  The best way to learn Remult is by following a tutorial of a simple Todo web app with a Node.js Express backend.
  