git: openjdk/jfx: jfx18: 8282766: Create release notes for JavaFX 18

[Johan Vos]

Changeset: df43d2bd
Author:    Abhinay Agarwal <abhinay_agarwal at live.com>
Committer: Johan Vos <jvos at openjdk.org>
Date:      2022-03-15 07:42:30 +0000
URL:       https://git.openjdk.java.net/jfx/commit/df43d2bdff884f6ea2f2c1f908504260db04e423

8282766: Create release notes for JavaFX 18

Reviewed-by: kcr, jvos

+ doc-files/release-notes-18.md