RFR: Clarified language around release notes

[Iris Clark]

On Thu, 13 Nov 2025 00:13:28 GMT, Jesper Wilhelmsson <jwilhelm at openjdk.org> wrote:

> The word "note" was used to refer to a release note, a release note sub-task, and a comment in a JBS issue - this could be confusing. Made it more explicit.
> Also updated the usage of Fix version for release notes which was not described correctly.

Marked as reviewed by iris (Reviewer).

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PR Review: https://git.openjdk.org/guide/pull/164#pullrequestreview-3456570116