Rename Questions to Ask -> Task-Specific Questions, remove redundant questions

Since product-marketing-context now captures foundational info (product, audience,
competitors, voice), removed redundant questions from these sections and renamed
them to clarify they are for task-specific context only.

Removed redundant questions from:
- competitor-alternatives (competitors, differentiator)
- copy-editing (audience, brand voice)
- email-sequence (audience)
- free-tool-strategy (product, audience problems)
- marketing-ideas (product, target customer)

Renamed section in all 23 skills with this pattern.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

skills/signup-flow-cro/SKILL.md

@@ -339,9 +339,8 @@ Organized by:
 
 ---
 
-## Questions to Ask
+## Task-Specific Questions
 
-If you need more context:
 1. What's your current signup completion rate?
 2. Do you have field-level analytics on drop-off?
 3. What data is absolutely required before they can use the product?