feat: 100 skills milestone — 7 new skills + quality improvements across all 93

New skills added:
- teaching-lesson-plan: structured lesson plans for any subject/audience/setting
- seo-content-brief: complete SEO briefs with intent, competitor gaps, and outline
- media-pitch: story-first journalist pitches with angle development framework
- change-management-plan: stakeholder analysis, comms strategy, adoption metrics
- workshop-facilitation-guide: activity instructions, decision protocols, facilitator moves
- sales-forecasting-model: pipeline model, scenario analysis, assumption log
- tax-planning-checklist: year-end tax planning across income, pension, CGT, reliefs

Quality improvements across all 93 existing skills:
- Standardised description format: "Verb the thing. Use when X. Produces Y."
- Added Required Inputs section to all skills missing it (prompts for missing info)
- Added Quality Checks section to all skills missing it (specific, not generic)
- Fixed broken multiline YAML descriptions
- Removed non-standard frontmatter keys (tool_integration, metadata blocks)

README updated to v6.0.0 with 100-skill count, new skill tables, and article series

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

skills/rice-prioritisation/SKILL.md

@@ -1,13 +1,21 @@
 ---
 name: rice-prioritisation
-description: Score and rank product initiatives using the RICE framework
-tool_integration: Jira
+description: "Score and rank product initiatives using the RICE framework. Use when asked to prioritise features, rank a backlog using RICE, score initiatives for quarterly planning, or apply an objective framework to a list of competing ideas. Produces a ranked RICE table with scores, quick wins and moonshot flags, dependency notes, and a recommended sequencing order."
 ---
+
 # RICE Prioritisation Skill
 
-## Purpose
 Apply consistent, criteria-based RICE scoring to a list of features or initiatives to produce an objective prioritisation ranking.
 
+## Required Inputs
+
+Ask the user for these if not provided:
+- **List of initiatives or features to score** (names and brief descriptions)
+- **Reach estimates** (users affected per quarter — from analytics if available)
+- **Impact estimates** (use the standard scale below)
+- **Effort estimates** (person-months — from engineering if available)
+- **Quarter or planning period**
+
 ## RICE Definitions (adapt to your context)
 - **Reach:** Number of users affected per quarter (use actual DAU/MAU data where available)
 - **Impact:** Effect on your primary metric — use scale: 3=massive, 2=high, 1=medium, 0.5=low, 0.25=minimal
@@ -24,8 +32,9 @@ RICE Score = (Reach × Impact × Confidence) / Effort
 4. Rank highest to lowest
 5. Flag any "quick wins" (high RICE score, low effort) and "moonshots" (high impact, high effort)
 6. Note dependencies between items that affect sequencing
+7. **Validate** — Cross-check: if the top-ranked item surprises the team, investigate whether an estimate is inflated. RICE is a tool, not a verdict.
 
-## Output Format
+## Output Structure
 
 ### RICE Prioritisation: [Backlog/Quarter]
 | Initiative | Reach | Impact | Confidence | Effort | RICE Score | Notes |
@@ -35,5 +44,16 @@ RICE Score = (Reach × Impact × Confidence) / Effort
 #### Recommended Sequence
 [Top 5 initiatives with rationale]
 
+#### Quick Wins (high score, low effort)
+[Items to pick up alongside bigger bets]
+
 #### Data Gaps to Address
 [What information would most improve scoring accuracy]
+
+## Quality Checks
+
+- [ ] Every initiative has all four RICE components estimated (even roughly)
+- [ ] Confidence is 50% for anything without data backing (not 100% as a default)
+- [ ] Quick wins and moonshots are explicitly called out
+- [ ] Dependencies that affect sequencing are noted
+- [ ] Any surprising ranking is investigated before accepting it