Rename project to SSAU Generator and restructure content

- Move projects into content/<project>/{docx,pptx} with shared assets/
- Flatten config paths; output = project name in project folder
- Add pptx --init scaffold; remove docx exe build
- Add feature-complete content/example; ignore content/* except example
- Rewrite README and AGENTS.md

content/example/pptx/slides/06-metrics.md

@@ -0,0 +1,8 @@
+# Метрики
+
+::: metrics
+4 | типа слайдов
+8 | типов блоков
+12 | директив разметки
+100% | возможностей
+:::