Add marketing-ideas skill with 140 SaaS marketing strategies

New skill containing 140 proven marketing ideas organized by category:
- Content & SEO (10 ideas)
- Competitor & Comparison (3 ideas)
- Free Tools & Engineering (12 ideas)
- Paid Advertising (14 ideas)
- Social Media & Community (12 ideas)
- Email Marketing (10 ideas)
- Partnerships & Programs (12 ideas)
- Events & Speaking (8 ideas)
- PR & Media (4 ideas)
- Launches & Promotions (10 ideas)
- Product-Led Growth (11 ideas)
- Content Formats (13 ideas)
- Unconventional & Creative (12 ideas)
- Platforms & Marketplaces (9 ideas)
- International & Localization (2 ideas)
- Developer & Technical (4 ideas)
- Audience-Specific (3 ideas)

Includes implementation guidance by stage, budget, and timeline.

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

README.md

@@ -29,6 +29,7 @@ Skills are markdown files that give AI agents specialized knowledge and workflow
 | [analytics-tracking](skills/analytics-tracking.md) | Set up tracking and measurement | "tracking," "GA4," "GTM," "events" |
 | [ab-test-setup](skills/ab-test-setup.md) | Plan and implement A/B tests | "A/B test," "split test," "experiment" |
 | [free-tool-strategy](skills/free-tool-strategy.md) | Plan engineering-as-marketing tools | "free tool," "calculator," "lead gen tool" |
+| [marketing-ideas](skills/marketing-ideas.md) | 140 SaaS marketing ideas and strategies | "marketing ideas," "growth ideas," "how to market" |
 
 ## Installation
 
@@ -123,6 +124,9 @@ You can also invoke skills directly:
 ### Growth Engineering
 - `free-tool-strategy` - Marketing tools and calculators
 
+### Strategy & Ideas
+- `marketing-ideas` - 140 SaaS marketing ideas
+
 ## Contributing
 
 Found a way to improve a skill? Have a new skill to suggest? PRs and issues welcome!