Update README.md

Author: maximecb

README.md

@@ -212,8 +212,8 @@ This is the only harness that uses `run_benchmark`'s argument, `num_itrs_hint`.
 
 ### Printing YJIT stats
 
-The `--yjit-stats` option of `./run_benchmarks.rb` allows you to print the diff YJIT stats
-at each iteration with the default harness.
+The `--yjit-stats` option of `./run_benchmarks.rb` allows you to print the diff of YJIT stats counters
+after each iteration with the default harness.
 
 ```
 ./run_benchmarks.rb --yjit-stats=code_region_size,yjit_alloc_size