message: docs: typo in env-vars.md
diff: This is the list of the actually supported env vars:
  - `NETWORK_KEY`: Zwave Network key
  -- `PORT`: The port to listent to for incoming requests. Default is `8091`
  +- `PORT`: The port to listen to for incoming requests. Default is `8091`
  - `HOST`: The host address to bind to. Default is `0.0.0.0`
  - `STORE_DIR`: The absolute path to the directory where all files will be stored. Default is `<path to your z2m dir>/store`
  