refactor: flatten pages structure and update setup.php for Git Sync

- Move pages/{fqdn}/pages/* to pages/{fqdn}/*
- Update setup.php to look at /user/pages/{hostname}
- Prepare for Git Sync to sync pages/ to user/pages/

pages/charters.turnsys.com/89.Handbook.SourceMaterial.engineering.common-issues/default.md

@@ -0,0 +1,18 @@
+---
+title: 'Shopify Event-Logging Bug'
+menu: 'Shopify Event-Logging Bug'
+---
+
+---
+title: Common Issues
+sidebar: Handbook
+showTitle: true
+---
+
+A page to host big issues raised by users (rather than small bugs) that we have certain answers for.
+
+### Shopify Event-Logging "Bug"
+
+Admin users who have PostHog setup for Shopify may experience their events being logged for another user. 
+
+This is not an issue with PostHog. Rather, this is due to a feature Shopify offers where it stores all the session data and lets you browse your website as if you were your client with all their cookies and local/session storage.