Design search box home page (for EPIC search engine #2706)

User story

I want to see that a search box is available, ready to help me navigate the complexity of decidim from the very front page. I want to have this search engine available while I navigate the site as well.

• Search box for menu: DONE --> Search topbar #2765
• Search box for home page

Related Issues

• EPIC: EPIC: Search Engine #2706
• MVP: Search engine MVP #2707
• Result page Design: Design of search results page #2591
• PR: Search topbar #2765 & Search homepage #3294