Update release notes for PSReadLine

[sdwheeler]

PR Summary

Update release notes for PSReadLine

• Fixes AB#400616

PR Checklist

• Descriptive Title: This PR's title is a synopsis of the changes it proposes.
• Summary: This PR's summary describes the scope and intent of the change.
• Contributor's Guide: I have read the contributors guide.
• Style: This PR adheres to the style guide.

[learn-build-service-prod]

Learn Build status updates of commit 6cf00eb:

✅ Validation status: passed

File	Status	Preview URL	Details
reference/5.1/PSReadLine/About/about_PSReadLine_Functions.md	✅Succeeded	View (powershell-5.1)
reference/5.1/PSReadLine/About/about_PSReadLine_Release_Notes.md	✅Succeeded	View (powershell-5.1)
reference/5.1/PSReadLine/About/about_PSReadLine.md	✅Succeeded	View (powershell-5.1)
reference/7.4/PSReadLine/About/about_PSReadLine_Functions.md	✅Succeeded	View (powershell-7.4)
reference/7.4/PSReadLine/About/about_PSReadLine_Release_Notes.md	✅Succeeded	View (powershell-7.4)
reference/7.4/PSReadLine/About/about_PSReadLine.md	✅Succeeded	View (powershell-7.4)
reference/7.5/PSReadLine/About/about_PSReadLine_Functions.md	✅Succeeded	View (powershell-7.5)
reference/7.5/PSReadLine/About/about_PSReadLine_Release_Notes.md	✅Succeeded	View (powershell-7.5)
reference/7.5/PSReadLine/About/about_PSReadLine.md	✅Succeeded	View (powershell-7.5)
reference/7.6/PSReadLine/About/about_PSReadLine_Functions.md	✅Succeeded	View (powershell-7.6)
reference/7.6/PSReadLine/About/about_PSReadLine_Release_Notes.md	✅Succeeded	View (powershell-7.6)
reference/7.6/PSReadLine/About/about_PSReadLine.md	✅Succeeded	View (powershell-7.6)

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel