Emphasizing that specifying an explicit encoding is wise.

Author: jglick

src/main/resources/org/jenkinsci/plugins/workflow/steps/durable_task/DurableTaskStep/help-encoding.html

@@ -2,5 +2,7 @@
     Encoding of process output.
     In the case of <code>returnStdout</code>, applies to the return value of this step;
     otherwise, or always for standard error, controls how text is copied to the build log.
-    If unspecified, uses the system default encoding of the node on which the step is run.
+    If unspecified, uses the system default encoding of the node on which the step is run,
+    but if there is any expectation that process output might include non-ASCII characters,
+    it is best to specify the encoding explicitly.
 </div>