Unhardcoding concurrent_compactors variable

Change-Id: Idd61c48f9d747aff897c7ddbc1a44a996c5cfa95
Tags: Customer-Related
diff --git a/README.rst b/README.rst
index f858209..da9d0b4 100644
--- a/README.rst
+++ b/README.rst
@@ -137,6 +137,7 @@
         name: 'Contrail'
         original_token: 0
         compaction_throughput_mb_per_sec: 16
+        concurrent_compactors: 1
         data_dirs:
         - /var/lib/cassandra
         id: 1