fix: add accessible labels to search and newsletter inputs

[slegarraga]

Adds explicit programmatic labels to the two text inputs that previously relied on placeholders or adjacent visible text.

• Search input now has a screen-reader-only label and an id.
• Newsletter input now associates its visible label with the field.

Verified with npm run lint and npx tsc --noEmit.

Closes #3

[royalpinto007]

Thanks a lot for this, @slegarraga, and welcome!

This is exactly the right fix. Associating the newsletter label with htmlFor/id and giving the search input a proper sr-only label means screen readers announce both correctly, rather than relying on placeholder text or nearby visible text. Nicely scoped, and all checks are green.

Merging now. If you enjoyed this one, there are a couple more open good first issue items (a real URL bug in CopyLinkButton, and a docs gap in CONTRIBUTING) and you would be very welcome to take either.