git: openjdk/leyden: leyden-ea1-release-notes: Update JEP titles, and add a general warning that flags will be renamed

[Mark Reinhold]

Changeset: 6f84e96b
Branch: leyden-ea1-release-notes
Author:    Mark Reinhold <mr at openjdk.org>
Date:      2024-08-15 17:21:10 +0000
URL:       https://git.openjdk.org/leyden/commit/6f84e96b7be30c2ad3ccb6db18610f0bcf92e167

Update JEP titles, and add a general warning that flags will be renamed

! README.md