fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/ui-design/skills/react-native-design/SKILL.md

@@ -430,11 +430,3 @@ const styles = StyleSheet.create({
 - **Memory Leaks**: Cancel animations and cleanup in useEffect
 - **Font Loading**: Use `expo-font` or `react-native-asset` for custom fonts
 - **Safe Area Issues**: Test on notched devices (iPhone, Android with cutouts)
-
-## Resources
-
-- [React Native Documentation](https://reactnative.dev/)
-- [React Navigation](https://reactnavigation.org/)
-- [Reanimated Documentation](https://docs.swmansion.com/react-native-reanimated/)
-- [Gesture Handler](https://docs.swmansion.com/react-native-gesture-handler/)
-- [Expo Documentation](https://docs.expo.dev/)