[jfx19] RFR: 8293615: Create release notes for JavaFX 19

[Kevin Rushforth]

Clean backport of JavaFX 19 release notes to `jfx19` branch.

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Commit messages:
 - 8293615: Create release notes for JavaFX 19

Changes: https://git.openjdk.org/jfx/pull/898/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=898&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293615
  Stats: 88 lines in 1 file changed: 88 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jfx/pull/898.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/898/head:pull/898

PR: https://git.openjdk.org/jfx/pull/898