Moldable Chat: Guiding chats through explanations

Let's ask the LLM for help with a less well-documented part of Glamorous Toolkit: rewrite rules. In this case, we ask it for a rewrite rule that removes self halt statements from the code.

c := GtLChat new
		markdownResponse;
		sendMarkdown: 'Provide the rewrite rule for removing all `self halt` statements from methods.'

The response looks confident, but it is typically wrong. We can nudge the LLM by providing relevant explanations in the system instructions:

c := GtLChat new
		markdownResponse;
		gtPageExplanation: 'Rewriting Pharo code by example';
		sendMarkdown: 'Provide the rewrite rule for removing all `self halt` statements from methods.'

This should produce a better result. If we combine that explanation with an expected response format that knows about rewrite rules, we can quickly explore queries and code transformations:

c := GtLChat new
		markdownResponse;
		gtPageExplanation: 'Rewriting Pharo code by example';
		addResponseFormatForMagrite: GtLRewriteRule named: 'RewriteRule';
		sendMarkdown: 'Provide the rewrite rule for removing all `self halt` statements from methods.'