RFR: 8282766: Create release notes for JavaFX 18

[Abhinay Agarwal]

Add release notes for JavaFX 18 to the repository

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Commit messages:
 - Create release notes for JavaFX 18

Changes: https://git.openjdk.java.net/jfx/pull/752/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=752&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282766
  Stats: 110 lines in 1 file changed: 110 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/752.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/752/head:pull/752

PR: https://git.openjdk.java.net/jfx/pull/752