docs: add ktx.yaml configuration reference (#200)

Adds a new Configuration section to the docs with a reference page that
covers every top-level block of ktx.yaml: connections, setup, storage,
llm, ingest, scan, agent, and memory. Each block lists fields, defaults,
accepted values, and a short YAML example, with a leading schematic that
groups blocks into inputs, compute, and persistence.

docs-site/content/docs/configuration/meta.json

@@ -0,0 +1,5 @@
+{
+  "title": "Configuration",
+  "defaultOpen": true,
+  "pages": ["ktx-yaml"]
+}