[clang] [NFC][Clang][Docs] Fix minor typos in Constant Interpreter doc. (PR #211608)

[Nikita Terentev via cfe-commits]

Seraphimt wrote:

> I was just about to push it when I noticed the change broke formatting a bit. Sorry for the premature approval - I didn't notice that in the inline diff 😅

@Tsche  I apologize for such an unfortunate oversight, the fix was so minor that I didn't check it much. Pipes should be fine now.

https://github.com/llvm/llvm-project/pull/211608