chore(pre-commit): document the potential for being out-of-date

Author: alexeagle

{{ .ProjectSnake }}/githooks/pre-commit

@@ -3,10 +3,14 @@
 git diff --cached --diff-filter=AM --name-only -z | xargs --null --no-run-if-empty bash -c '
   if [ $# -gt 0 ]; then
     echo "Formatting staged files: $@"
+    # Avoid running bazel to build the formatter.
+    # In theory it's more correct to build it since the one in bazel-out may be out-of-date.
+    # However a 'git commit' operation should always be fast, and accidental analysis or action cache misses are common.
+    # So we take the tradeoff of running the existing binary if it exists.
     if [ -e "bazel-out/bazel_env-opt/bin/tools/bazel_env/bin/format" ]; then
       bazel-out/bazel_env-opt/bin/tools/bazel_env/bin/format "$@"
     else
-      bazel run //:format -- "$@"
+      bazel run //tools/format -- "$@"
     fi
 
     # Check if any of the staged files were modified by the formatter