Enforcing 3 Demos in MIPROv2 Meta Prompt

[klopsahlong]

Previous Behavior:

In some cases, only 1 demo was included in the meta-prompt. This occurred when few-shot examples were generated with a size of 1 (since the size is randomly chosen between 1: max_bootstrap_fewshot), and when max_bootstrap_fewshot is set to 1.

New behavior:

We wanted for the # of few-shot examples in the prompt to always equal 3 to avoid potential overfitting of the generated instruction to a single example.

The fix:

We will essentially did the following:
prompt_demos = (my_demos + all_other_demos)[:min(3, len(my_demos + all_other_demos))]

Which will give us 3 demos for all prompts, unless there are less than 3 demos total across all bootstrapped few-shot examples. Note that we keep the demos empty for a single instruction generation, just in case demos end up being counter productive in the meta prompt.

A few other minor additions:

• Renamed some variables for legibility
• Added back in the generated module description to the meta-prompt, which summarizes what the module we're generating an instruction for is responsible for