[clang] Docs: ambiguous use of "explicitly" in [[clang::no_specializaiton]] (PR #143839)

[Nikolas Klauser via cfe-commits]

philnik777 wrote:

> > Thank you all for weighing in here. It seems there is some disagreement on how to move forward with this. I believe the current change addresses the initial issue this PR is tied to, which aimed to clarify this attribute affects more than just explicit specializations defined by users.
> > I'm happy to make a change here to be more verbose like what @frederick-vs-ja suggested if that is what is preferred by the maintainers.
> 
> @philnik777 Do you have any preference or opinion on how to proceed?

I'm OK with Fredericks wording. I'd also be fine with something like "user-defined explicit or partial specialization"

https://github.com/llvm/llvm-project/pull/143839