Function prependSystemPrompt

prependSystemPrompt(program: Program, text: string): Program
Puts a system message in front of a program's conversation.
Parameters
- program: Program
  Program to edit.
- text: string
  System prompt text.
Returns Program
A new program; the input is left untouched.
Example
```
async execute(request, ctx) {
  return ctx.invoke(upstream, prependSystemPrompt(request, "Be concise."));
}
```