Update specification.md

Co-authored-by: Ricardo Zanini <1538000+ricardozanini@users.noreply.github.com>

Author: cdavernas

specification.md

@@ -4509,7 +4509,7 @@ Error definitions are [RFC 7807](https://datatracker.ietf.org/doc/html/rfc7807)
 
 Property `instance` identifies the component within a workflow definition from which the described error originates. It is set by runtimes when throwing an error.
 
-For example, in the above definition, the source '/states/0/actions/0' indicates that the error originates from the execution of the first action of the first state of the workflow definitions.
+For example, in the above definition, the source `/states/0/actions/0` indicates that the error originates from the execution of the first action of the first state of the workflow definitions.
 This helps both users and implementers to describe and communicate about origins of errors without technical, technology/platform specific knowledge or understanding.
 
 Property `type` is an URI used to identify the type of the error.