Repait LaTeX in benchmark docs

ref_app/src/app/benchmark/readme.md

@@ -43,7 +43,7 @@ a wide range of microcontroller _performance_ _classes_.
 Consider, for instance,
 [app_benchmark_pi_agm.cpp](https://github.com/ckormanyos/real-time-cpp/blob/master/ref_app/src/app/benchmark/app_benchmark_pi_agm.cpp)
 which exercises the benchmark of type `APP_BENCHMARK_TYPE_PI_AGM`.
-This benchmark compute ${\sim}~50~{\ldots}~100$ decimal digits of the mathematical constant
+This benchmark computes ${\sim}50{\ldots}100$ decimal digits of the mathematical constant
 $\pi$ using a Gauss AGM method with help
 from the [`decwide_t`](https://github.com/ckormanyos/real-time-cpp/blob/master/ref_app/src/math/wide_decimal/decwide_t.h)
 template class.