Move synced content to _build/ directory

Separates auto-synced content (guides, tutorials) from hand-authored
files by placing them under _build/. Adds Jekyll include config so
the underscore-prefixed directory is processed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: chrismo

_build/.readme

@@ -0,0 +1 @@
+Do not edit files in this directory. Content is auto-synced from superdb-mcp.

tutorials/index.md _build/tutorials/index.mdtutorials/index.md renamed to _build/tutorials/index.md

@@ -5,3 +5,4 @@ url: "https://chrismo.github.io"
 baseurl: "/superkit"
 permalink: pretty
 color_scheme: dark
+include: ["_build"]