Navigation, Routing and Theming added

src/app/rooms/rooms.component.css

src/app/rooms/rooms.component.html

src/app/rooms/rooms.component.spec.ts

src/app/rooms/rooms.component.ts

src/app/start/start.component.css

src/app/start/start.component.html

src/app/start/start.component.spec.ts

src/app/start/start.component.ts

src/assets/THD-Logo.png

src/custom-theme.scss

src/index.html

src/styles.css