New tutorial for: PromptNode Basics

[TuanaCelik]

Describe the tutorial you would like to see here
I will create a second issue for a more advanced tutorial. However, for the PromptNode basics I would suggest we start with:

• Initializing a PromptNode with various models
• The default PromptTemplates
• Defining your own PromptTemplate

@agnieszka-m please add any input about how this can be 'task' oriented.

Additional context
I think using the PromptNode in a pipeline is slightly more advanced and could be too distracting to have an intro tutorial that covers this. So I suggest a separate one for that

[x] I've checked the existing tutorials