Add support for beta to Uptime Kuma

[bannert1337]

🌟 Briefly describe the feature

Add option to use the beta version

📝 Detailed description

When installing with the script, let the user select between the stable and beta versions.

💡 Why is this useful?

Uptime Kuma's last stable release was on 20/12/2024 and most development goes towards version 2, which is in beta, but generally stable.

[MickLesk]

No. We only use stable Scripts. Not betas. Beta can be installed by user himself, If he know what he do. That bloat our Scripts massive. Because some Breaking Changes & so on