Clarify autocomplete share type values

[mzl2233]

This clarifies the autocomplete API documentation by listing the valid shareTypes values next to the guest-account example, including 8 for guest accounts and the default user value. It also fixes the surrounding wording so readers can tell which query parameter to use and what happens when it is omitted.

[skjnldsv]

Hey! Thanks for the PR.
Could this be a table instead please? :)

I think that would look much better

[skjnldsv]

Done, converted to a table directly on the branch.

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