[Docs]: Tutorials/github-oauth/svelte reformat

[T1xx1]

Changes

• Added some missing file paths in code examples
• Update +page.server.ts -> routes/+page.server.ts for clarity
• Fix an import mismatch in "Sign out user" where lucia was used as auth but imported as lucia.
• General reformat. Spacing is essential for readability as docs need to be
• DB/ORM directives. I didn't know I had to change those when I used the code for the first time. Better specify.

[T1xx1]

Can you also format the docs by running pnpm format in the repository root?

Yep, working on

[T1xx1]

Formatted

[pilcrowOnPaper]

Thanks!