Add comprehensive documentation for all project sections

Introduced new and updated documentation files across the docs/ directory, including project structure guides, function library references, and standardized READMEs for ct, install, vm, tools, api, and misc. This update fully documents all nine function libraries, provides quick start and learning paths, and mirrors the project structure for easier navigation and contribution.

docs/misc/cloud-init.func/CLOUD_INIT_FUNC_FLOWCHART.md

@@ -0,0 +1,28 @@
+# cloud-init.func Flowchart
+
+Cloud-init VM provisioning flow.
+
+## Cloud-Init Generation and Application
+
+```
+generate_cloud_init()
+    ↓
+generate_user_data()
+    ↓
+setup_ssh_keys()
+    ↓
+Apply to VM
+    ↓
+VM Boot
+    ↓
+cloud-init phases
+├─ system
+├─ config
+└─ final
+    ↓
+VM Ready ✓
+```
+
+---
+
+**Last Updated**: December 2025