docs: update adapter static doc for github page deployment

[mengxi-ream]

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The document solved the problem that people can't see css in their github page deployment with static adapter
https://www.reddit.com/r/sveltejs/comments/w30mty/not_showing_any_css_styling_when_hosted_as_static/

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[Rich-Harris]

preview: https://svelte-dev-git-preview-kit-13302-svelte.vercel.app/

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[ghostdevv]

Suggested change

If you're not using GitHub actions to deploy your site (for example, you're pushing the built site to its own repo), add an empty `.nojekyll` file in your `static` directory to prevent Jekyll from interfering. If you use `gh-pages` to push the build folder to your repository, you need to add the `-t` option to the command `npx gh-pages -d build -t` to include dot files (e.g., `.nojekyll`) in your build branch.

If you're not using GitHub actions to deploy your site (for example, you're pushing the built site to its own repo), add an empty `.nojekyll` file in your `static` directory to prevent Jekyll from interfering. Alternatively, if you're using the [`gh-pages`](https://www.npmjs.com/package/gh-pages) cli, you should add the `--nojekyll` flag.

Slight tweak to use this option instead, as may reduce accidentally committing a dotfile you didn't intend