fix: correct the clang-format example hgrc so that it actually works There are three changes here: * Remove -i from `command`, it causes fix to eat your file and empty it out * Add `set:` to pattern, otherwise this is interpreted as just a glob * Switch `listfile:` to `include:`; `listfile:` is relative to the current working directory, while `include:` is relative to the repo root. This makes it so that you don't receive errors when running outside of the repo root about being unable to find the file. Differential Revision: https://phab.mercurial-scm.org/D7618