C++: Slightly tweak change note to make it more consistent with others

[jketema]

Mostly the change notes of:

• C++: Support non-type template parameters #18320
• C++: Support arguments and instantiations of template template parameters #18360

Pull Request checklist

All query authors

• A change note is added if necessary. See the documentation in this repository.
• All new queries have appropriate .qhelp. See the documentation in this repository.
• QL tests are added if necessary. See Testing custom queries in the GitHub documentation.
• New and changed queries have correct query metadata. See the documentation in this repository.

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[andersfugmann]

LGTM