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/94.Handbook.SourceMaterial.engineering.releasing-python/default.md

@@ -0,0 +1,17 @@
+---
+title: 'How to Release'
+menu: 'How to Release'
+---
+
+---
+title: Releasing a New Version (Python Library)
+sidebar: Handbook
+showTitle: true
+---
+
+## How to Release
+1. Increase `VERSION` in `posthog/version.py`
+2. Update `CHANGELOG.md` with a short summary of the changes
+3. run `make release` and `make release_analytics`
+4. `git commit -am "Release X.Y.Z."` (where X.Y.Z is the new version)
+5. `git tag -a X.Y.Z -m "Version X.Y.Z"` (where X.Y.Z is the new version).