fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/startup-business-analyst/skills/startup-financial-modeling/SKILL.md

@@ -459,23 +459,6 @@ Compare key metrics to similar companies at similar stage.
 **Investor Feedback:**
 Share model with advisors or investors for feedback on assumptions.
 
-## Additional Resources
-
-### Reference Files
-
-For detailed model structures and advanced techniques:
-
-- **`references/model-templates.md`** - Complete financial model templates by business model
-- **`references/unit-economics.md`** - Deep dive on CAC, LTV, payback, and efficiency metrics
-- **`references/fundraising-scenarios.md`** - Modeling funding rounds and dilution
-
-### Example Files
-
-Working financial models with formulas:
-
-- **`examples/saas-financial-model.md`** - Complete 3-year SaaS model with cohort analysis
-- **`examples/marketplace-model.md`** - Marketplace GMV and take rate projections
-- **`examples/scenario-analysis.md`** - Three-scenario framework with sensitivities
 
 ## Quick Start
 
@@ -490,5 +473,3 @@ To create a startup financial model:
 7. **Create scenarios** - Conservative, base, optimistic
 8. **Validate assumptions** - Sanity check and benchmark
 9. **Integrate fundraising** - Model funding rounds and milestones
-
-For complete templates and formulas, reference the `references/` and `examples/` files.