docs: add Pezkuwi-SDK documentation

- Technical documentation
- SDK guides
- Architecture overview
- Whitepaper
- Contributor guides

mermaid/IA.mmd

@@ -0,0 +1,12 @@
+flowchart TD
+    dot[pezkuwichain.io] --> devhub[pezkuwi_sdk_docs]
+
+    devhub --> pezkuwi_sdk
+    devhub --> reference_docs
+    devhub --> guides
+	devhub --> external_resources
+
+    pezkuwi_sdk --> substrate
+    pezkuwi_sdk --> frame
+    pezkuwi_sdk --> xcm
+	pezkuwi_sdk --> templates