[Feature] Persisting initial chat context message

[elendil7]

FEATURE REQUEST:

Add option to set persisting initial chat context message, that lingers between conversations.

E.g., "You are a helpful assistant. You can help me by answering my questions. You can also ask me questions" will appear as the starting message in EVERY new conversation.

Added bonus: give user ability to save a pool of these initial contexts, that can be selected on through, for example, a dropdown menu on every new chat.

Thank you for your time.