Adding Posts Index | markdown sitegen 4

Added posts index, added config file for site title, and other cool stuff

Timestamps

• 0:00 Demo
• 0:20 Posts index code walkthrough
• 1:29 Site title / config file walkthrough
• 2:22 Date, code snippets issues
• 3:13 Docs vault / Roadmap (NEW)
• 3:36 What’s Next