message: Clarifying file tokens
diff: @@ -101,9 +101,16 @@ paths:
  ### File tokens
  -Files are uploaded with a token within their metadata. This will mean that files are visible without authentication, if the file token is passed in as a query parameter.
  +When you upload a file to Hasura Backend Plus, a token is automatically added to the file metadata. This is unique for the file, and can be used as an access token.
  +You can create a `validToken` function, and use that to allow access to the file, even if a user is unauthenticated.
  -You can access query parameters on the `request` object:
  +We can define a rule to allow access to this image if the right token (in this case `c9aa7344-1b4c-42d2-81c0-48ee401a3eeb`) is present:
  +
  +``` txt
  +/storage/o/private/secret-image.jpg?token=c9aa7344-1b4c-42d2-81c0-48ee401a3eeb
  +```
  +
  +The token is sent as a query parameter, which you can access on the `request` object. You can check the token against the `resource.Metadata.token` variable:
  ``` yaml
  functions:
  @@ -117,16 +124,9 @@ functions:
  validToken: 'return request.query.token === resource.Metadata.token'
  paths:
  /private/:fileId:
  - list: 'return false'
  read: 'validToken()'
  ```
  -The following URL will work for a file called `image.jpg` that has a token of `04f1449d-e567-44c9-a5b8-0f21b2eaa261`:
  -
  -``` txt
  -/storage/o/private/image.jpg?token=04f1449d-e567-44c9-a5b8-0f21b2eaa261
  -```
  -
  ## Functions
  > It is not possible to call functions inside other functions
  