Update transforms.md

[jortvanleenen]

Fixes incorrect bracket parenthesis order.

Motivation and Context

I put a fragment of example code in my IDE for re-use and noticed that I got a linter error. I realised that a parenthesis and bracket were mixed around.

How Has This Been Tested

N/A, basic Python syntax

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed. (unchecked, but no code change)