docs: add `Dropdown` samples #7575

Job	Run time
Tests / Static Checks	2m 38s
Tests / Playwright Tests (chrome)	2m 59s
Tests / Playwright Tests (firefox)	3m 15s
Tests / Build	1m 14s
Tests / A11y Tests	4m 41s
Tests / Unit Tests	3m 7s
Artifacts / Build	4m 57s
Visual Tests / Chromatic	1m 58s
Artifacts / Deploy	30s
	25m 19s

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