MINOR: Document improvement
Reviewers: Manikumar Reddy
### JMH-Benchmark module
This module contains benchmarks written using [JMH](https://openjdk.java.net/projects/code-tools/jmh/) from OpenJDK.
-Writing correct micro-benchmarks is Java (or another JVM language) is difficult and there are many non-obvious pitfalls (many
+Writing correct micro-benchmarks in Java (or another JVM language) is difficult and there are many non-obvious pitfalls (many
due to compiler optimizations). JMH is a framework for running and analyzing benchmarks (micro or macro) written in Java (or
another JVM language).
