[Feature] Installer slideshow

[ItsSim]

Is your feature request related to a problem? Please describe.
The backdrop that displays when doing a full installation of the game was meant to be a slideshow of in-game images, to show-off how awesome FreeSO is! But I never got around to finishing it, so it's always been a static image of Sunrise Crater.

Describe the solution you'd like
The complete installation backdrop should be made into a slideshow with game screenshots: showing Sims having fun, lot builds, weird moments! Any screenshots that would make the user excited to try the game.

There are two tasks to be done here:

• Obtain HD game screenshots.
• Add the slideshow logic (just a simple timer, and change the background every x seconds): fsolauncher.pug, client.js

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.