[docs] Scaffold reference guides + README Documentation section

- Documentation/{Extensions,SwiftUI,UIKit}.md shells with category headings + TOC
- README: Documentation table linking all 4 guides
- footer: drop the second github badge, keep the resume link

Documentation/UIKit.md

@@ -0,0 +1,40 @@
+# LCEssentials — UIKit
+
+UIKit-era helpers: programmatic layout & constraints, view/control extensions,
+navigation, table/collection helpers, and drop-in components (image picker, image
+zoom, snackbar, GIF loading).
+
+Foundation/value-type helpers are in [Extensions.md](Extensions.md); SwiftUI
+helpers in [SwiftUI.md](SwiftUI.md).
+
+Every section is a collapsible block — click a heading to expand it.
+
+## Contents
+
+- [Layout & Constraints](#layout--constraints)
+- [Views & Controls](#views--controls)
+- [Navigation & Controllers](#navigation--controllers)
+- [Collections & Tables](#collections--tables)
+- [Media & Components](#media--components)
+
+---
+
+## Layout & Constraints
+
+<!-- batch 9 -->
+
+## Views & Controls
+
+<!-- batch 10 -->
+
+## Navigation & Controllers
+
+<!-- batch 11 -->
+
+## Collections & Tables
+
+<!-- batch 12 -->
+
+## Media & Components
+
+<!-- batch 13 -->