Update new course and guide workflow - welcome issue ticket message

[afewell]

The new course and new guide workflows create an issue ticket in a newly created course/guide to provide a welcome message to the requestor that the new repository is available and associated details.

Currently there is a bug in the workflow such that the issue ticket is created with a single variable "$body" as the body of the issue ticket. When working properly, the workflow should replace the $body variable with the text contents of the message, and not the name of the variable.

These workflows need to be updated to ensure the variable is recognized and associated values are inserted into the issue ticket body.