Add some missing Release Notes entries

[AliSoftware]

This release, we got some PRs made by external contributors from @gitstart 🎉 … but we completely forgot to tell them at the time to add entries for their changes to the RELEASE-NOTES.txt file as part of their PR. So this PR adds the relevant entries:

• Not only to the RELEASE-NOTES.txt file (the one we expect contributors to update when they do a new PR to describe the changes, assuming those changes are interesting enough to end users to make it to the release notes)
• But also to the WordPress/{jetpack_,}metadata/release_notes.txt files that are usually auto-generated by our release tooling when it extracts the entries from RELEASE-NOTES.txt. Since I already ran that tooling earlier today when I did the code freeze before adding those missing entries, I had to update those manually to simulate them being extracted from the RELEASE-NOTES.txt file during code-freeze.

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PS: We need this PR to land ASAP so that our freelance writer can use those files (from trunk once they will have landed) to write nice editorialized copies for those entries, so we can then send that editorialized copy for release notes to translation this week.

cc @vanessamaartinstt FYI as you might want to include those additional entries in the upcoming Call for Testing you'll likely be drafting today 🙂

[peril-wordpress-mobile]

	Warnings
⚠️	The PlayStoreStrings.po file must be updated any time changes are made to release notes

Generated by 🚫 dangerJS

[wpmobilebot]

📲 You can test these changes on Jetpack by downloading jetpack-installable-build-pr17245-e5cd329.apk

	💡 Scan this QR code with your Android phone to download and install the APK directly on it.
	App	Jetpack
	Build Flavor	Jalapeno
	Build Type	Debug
	Commit	e5cd329

Note: This installable build uses the JalapenoDebug build flavor, and does not support Google Login.

[wpmobilebot]

📲 You can test these changes on WordPress by downloading wordpress-installable-build-pr17245-e5cd329.apk

	💡 Scan this QR code with your Android phone to download and install the APK directly on it.
	App	WordPress
	Build Flavor	Jalapeno
	Build Type	Debug
	Commit	e5cd329

Note: This installable build uses the JalapenoDebug build flavor, and does not support Google Login.

[spencertransier]

Looks great! Thanks for explaining why the manual copying to metadata/release_notes.txt was necessary 🙂