UI Components

This article stub needs descriptive content and example usage for each component declared in Rocket.Chat UI to improve ease of development and prevent furthering multiple components being contributed for the same purpose with conflicting styles and usage. Can you help?
Example content:

Side Nav

Describe usage for template development contributions
Provide example usage and html structure / class names of nested elements
  • Content
    • Admin Link
    • Input Line
    • Button
  • Account Box
    • Status
    • Account Link
  • Rooms List
    • Header
    • Item
    • Item List