ci: migrate from Netlify to a different provider

[AnsonH]

Description

Currently we deploy the application to Netlify 👇

https://github.com/AnsonH/plinko-game/blob/084cc5d482d7e2b7fcdd9e34b8800661d73a6e4b/.github/workflows/deploy.yml#L51

To my surprise, the website is getting more popular and it's starting to eat up my free 100GB/month bandwidth 😥

Option 1 - GitHub Pages

Since we're using static site generation, SvelteKit supports deployment to GitHub Pages: https://svelte.dev/docs/kit/adapter-static#GitHub-Pages

Drawbacks:

• Preview PR sites no longer supported
• Need to redirect https://plinko-web-game.netlify.app to the new GitHub pages URL

Option 2 - Cloudflare Pages

https://pages.cloudflare.com/