Fix the exception format to make it work better with the new bug template

[daxian-dbw]

PR Summary

With the new bug template, the exception report printed by PSReadLine is supposed to be copied to the "Exception report" section which uses console render. So there is no need to warp the keys and exception stack trace in code blocks (backticks).
Also fix a typo.

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Make sure you've added one or more new tests
• Make sure you've tested these changes in terminals that PowerShell is commonly used in (i.e. conhost.exe, Windows Terminal, Visual Studio Code Integrated Terminal, etc.)
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed at PowerShell-Docs
    • Doc Issue filed:

Microsoft Reviewers: Open in CodeFlow