docs: S2 docs fixes from testing (#9144)
* fix llms.txt link
* hide mobile ToC if there is just one section
* add copy feedback to icons search
* add message to press icon items to copy
* lint
* fix llms.txt link to open in new tab
* remove Archived releases header link
* fix overflow on useDrop page
* increase text size for info message
* dedupe icons search code where possible
