[Docs] Display use of colon for separating apis,models,supportingFiles

Created by: aderito7

Just came across this bit of documentation that had me confused for a little while

openApiGenerate {
    globalProperties = [
        apis: "",
        models: "User,Pet"
    ]
}

I've soon learnt that the separator that should be used is a colon and not comma (i.e. User:Pet and not User,Pet). If correct, was hoping this could be updated for any travelers arriving on the docs and spare them the head-scratching I endured.