refactor: split 21 over-500-line skills into SKILL.md + references (#296)

engineering/codebase-onboarding/references/output-format-templates.md

@@ -0,0 +1,41 @@
+# codebase-onboarding reference
+
+## Output Formats
+
+### Notion Export
+
+```javascript
+// Use Notion API to create onboarding page
+const { Client } = require('@notionhq/client')
+const notion = new Client({ auth: process.env.NOTION_TOKEN })
+
+const blocks = markdownToNotionBlocks(onboardingMarkdown) // use notion-to-md
+await notion.pages.create({
+  parent: { page_id: ONBOARDING_PARENT_PAGE_ID },
+  properties: { title: { title: [{ text: { content: 'Engineer Onboarding — MyApp' } }] } },
+  children: blocks,
+})
+```
+
+### Confluence Export
+
+```bash
+# Using confluence-cli or REST API
+curl -X POST \
+  -H "Content-Type: application/json" \
+  -u "user@example.com:$CONFLUENCE_TOKEN" \
+  "https://yourorg.atlassian.net/wiki/rest/api/content" \
+  -d '{
+    "type": "page",
+    "title": "Codebase Onboarding",
+    "space": {"key": "ENG"},
+    "body": {
+      "storage": {
+        "value": "<p>Generated content...</p>",
+        "representation": "storage"
+      }
+    }
+  }'
+```
+
+---