Biome doesn't support formatting all file types in the repo

[Lms24]

As discussed in our Daily, let's use prettier for formats that aren't supported by Biome:

• markdown
• svelte
• css (?)

I don't think we have .astro or .vue components which also aren't supported yet

[anonrig]

It seems Svelte files are not supported by Prettier as well. When trying to run Prettier with it, it gives the following error;

[error] No parser could be inferred for file "/Users/yagiz/coding/sentry-javascript/packages/e2e-tests/test-applications/sveltekit-2/src/routes/+page.svelte".
[error] No parser could be inferred for file "/Users/yagiz/coding/sentry-javascript/packages/e2e-tests/test-applications/sveltekit-2/src/routes/building/+page.svelte".
[error] No parser could be inferred for file "/Users/yagiz/coding/sentry-javascript/packages/e2e-tests/test-applications/sveltekit/src/routes/+page.svelte".
[error] No parser could be inferred for file "/Users/yagiz/coding/sentry-javascript/packages/e2e-tests/test-applications/sveltekit/src/routes/building/+page.svelte".
[error] No parser could be inferred for file "/Users/yagiz/coding/sentry-javascript/packages/svelte/test/components/Dummy.svelte".