[clang-tidy][NFC] add comment in llvm-use-ranges for add_new_check.py (#159927)

`add_new_check.py` deps on heuristic method (find special words) to
detect whether check support auto fix.
This PR wants to add comment in `llvm-use-ranges` to make it work.

Author: HerrCai0907

clang-tools-extra/clang-tidy/llvm/UseRangesCheck.cpp

@@ -8,6 +8,8 @@
 
 #include "UseRangesCheck.h"
 
+// FixItHint - Let the docs script know that this class does provide fixits
+
 namespace clang::tidy::llvm_check {
 
 namespace {