tutorial/plugins: mention that plugins require admin privileges

Summary

• tutorial/plugins: mention that plugins require admin privileges

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• Close #323 (closed)
• Cherry-pick to: none
• Staging: https://docs.binary.picodata.io/picodata/at_plugins_admin/tutorial/plugins/

added docs: update label

assigned to @a.tolstoy

requested review from @UngiftedPoet

approved this merge request

changed the description

merged