Update README.md Zero Shot Code block

[Owaiskhan9654]

Changing facebook/bart-large-mnli to cross-encoder/nli-deberta-base works for Zero Shot classification Interpret. @cdpierse

PR Description

Motivation and Context

References issue: # (ISSUE)
#133 #125 #70

Tests and Coverage

I have tested these changes locally and in Google Colab. Works in both the scenarios

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Docs (Added to or improved Transformers Interpret's documentation)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Final Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[cdpierse]

Nice thank you, sorry for being so late to this.