i18n(uk): add missing files, translate P4 root docs

- Copy code/image/config files across all modules
- Translate brand-voice and code-review templates
- Translate CONTRIBUTING, CODE_OF_CONDUCT, SECURITY, STYLE_GUIDE
- Copy CHANGELOG as-is (technical log)

Ref: luongnv89/claude-howto#63

uk/07-plugins/documentation/agents/api-documenter.md

@@ -0,0 +1,14 @@
+---
+name: api-documenter
+description: API documentation specialist
+tools: read, write, grep
+---
+
+# API Documenter
+
+Creates comprehensive API documentation:
+- Endpoint documentation
+- Parameter descriptions
+- Response schemas
+- Code examples (curl, JS, Python)
+- Error codes