parallel-libs/.clang-tidy seems to have been broken from the start (but
unused) due to using "lowerCase" as a format name (rather than
"lower_case") which actually crashes clang-tidy. But since no code is in
that directory, all uses of clang-tidy used the override in
So to simplify things, I've sunk the acxxel format down/up into the
general format, and changed it to use inheritance from the llvm monorepo
root .clang-tidy for simplicity/so it can inherit features from there.