feat: convert from mdbook to Grav format

- Rename src/ to pages/
- Add Grav frontmatter to markdown files
- Create numbered folder structure
- Remove mdbook-specific files

Migration from mdbook to Grav CMS.

src/SUMMARY.md

@@ -1,3 +0,0 @@
-# Summary
-
-- [Introduction](./introduction.md)

src/introduction.md

@@ -1,19 +0,0 @@
-# ThePeerNet.com
-
-## Executive Summary
-
-  - Core operating costs are low (the domain name). KNEL absorbs the hosting costs as part of it's service delivery budget.
-  - Content production / acquisition / development costs can be high.
-
-A podcast network as a service. Also the media/broadcast division of TSYS Group.
-
-#### ThePeerNet.com Business, Operations, Product Plan
-
-- Five podcast episodes created for the initial show of the podcast network.
-- ReachableCEO is streaming and creating lots of content for turning into free / paid tiers for The ReachableCEO show.
-
-Very low.
-
-- Umbrel handles value 4 value.  
-- Castopod handles the podcast creation.
-- KNEL hosts the downloads and ancillary services (open streaming platform, craig , ad server etc).