add readme for spark

Author: breedx-splk

instrumentation/spark-2.3/README.md

@@ -0,0 +1,10 @@
+# Spark Instrumentation
+
+This instrumentation is for 
+[Spark](https://github.com/perwendel/spark) -
+a tiny web framework for Java. It is also sometimes referred to as 
+"Spark Java" to differentiate it from Apache Spark.
+
+This instrumentation is NOT for Apache Spark.
+
+The instrumentation here facilitates tracing by generating HTTP SERVER spans.