Update Vercel guide

[ysfchn]

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

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Updated Vercel guide to recommend using a custom command for obtaining musl binary of Zola, since Vercel's own Zola preset always gets glibc version even when it couldn't run on its own due to lacking glibc version in the system image.

echo "${ZOLA_VERSION:-"latest"}" | sed '/^latest$/!s/\(.*\)/tags\/v\1/' | \
    xargs -I% curl -fsSL "https://api.github.com/repos/getzola/zola/releases/%" | \
    grep -oP "\"browser_download_url\": ?\"\\K(.+linux-${ZOLA_LIBC:-"musl"}\\.tar\\.gz)" | \
    xargs curl -fsSL | tar -xz

Feels hacky than ever but I couldn't get to simplify than this.

Just for the reference, Vercel has acknowledged the issue and said working on a fix to use musl binaries onwards but I'd prefer having the command on the Zola docs anyway.

[Keats]

Can you revert the formatting changes?

[ysfchn]

Sure, should be done now 👍