Change formatting of code blocks in Tensorboard profiler tutorial

[kiersten-stokes]

Fixes #1901

Description

After these changes, the HTML is being rendered as it was before (expected behavior), but the corresponding code blocks in the Colab notebook will be rendered properly.

Before (following link from tutorial HTML):

After (rendered in VSCode):

Checklist

• The issue that is being fixed is referred in the description (see above "Fixes #ISSUE_NUMBER")
• Only one issue is addressed in this pull request
• Labels from the issue that this PR is fixing are added to this pull request
• No unnessessary issues are included into this pull request.

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[svekars]

Thanks, @kiersten-stokes!