OpenSMT: Improve description of the new option, as suggested by @kfriedberger

Author: daniel-raffler

src/org/sosy_lab/java_smt/solvers/opensmt/OpenSmtSolverContext.java

@@ -53,7 +53,11 @@ static class OpenSMTOptions {
     @Option(secure = true, description = "Algorithm for LRA interpolation")
     int algLra = 0;
 
-    @Option(secure = true, description = "Simplify interpolants before they are returned")
+    @Option(
+        secure = true,
+        description =
+            "Level of simplification for interpolants,"
+                + "ranging from 0 (no simplification) to 4 (maximum simplification).")
     int simplifyInterpolants = 0;
 
     final int randomSeed;