Merge pull request #110 from jeffret-b/documentQuotes

Highlight importance of using single-quotes.

README.md

@@ -43,6 +43,18 @@ withCredentials([usernamePassword(credentialsId: 'amazon', usernameVariable: 'US
 }
 ```
 
+#### Note
+
+You should use a single quote (`'`) instead of a double quote (`"`) whenever you can. 
+This is particularly important in Pipelines where a statement may be interpreted by both the Pipeline engine and an external interpreter, such as a Unix shell (`sh`) or Windows Command (`bat`) or Powershell (`ps`). 
+This reduces complications with password masking and command processing. 
+The first step in the above example properly demonstrates this. 
+The next two steps use the basic Pipeline `echo` step. 
+The first one references the Groovy variable and needs no quotes. 
+The second one needs to use double quotes, so that the interpolation is performed in Groovy.
+
+For more information, see the Pipeline step reference for [Credentials Binding Plugin](https://www.jenkins.io/doc/pipeline/steps/credentials-binding/).
+
 ## Changelog
 
 See [GitHub Releases](https://github.com/jenkinsci/credentials-binding-plugin/releases) for new releases,