DOC-2446: Add TINY-10869 release note entry

[FarzadHayat]

Ticket: DOC-2446

Site: Staging branch

Changes:

• Add TINY-10869 release note entry: Improve merging of inserted inline elements by removing nodes with redundant inheritable styles.

Pre-checks:

• [x] Branch prefixed with feature/<version>/, hotfix/<version>/, staging/<version>/, or release/<version>/
• [-] modules/ROOT/nav.adoc has been updated (if applicable)
• [-] Files has been included where required (if applicable)
• [-] Files removed have been deleted, not just excluded from the build (if applicable)
• [x] Files added for New product features, and included a release note entry.

Review:

• [x] Documentation Team Lead has reviewed

[FarzadHayat]

@MitchC1999 Thank you for the improvements.