create search box

[tkilgour]

Adds search box according to #120.

[sergical]

@tkilgour Thomas, this is a great feature! However, when I search for something wild like ksj;af, it shows the error on the lists, but the show notes are still there making me feel like there is something in the notes that matches the result. Maybe if the search is there, we can assume the show notes can display a "not found" state as well? because if i search for "style", then add something to it like "styleiafdas" it keeps the "Style" highlighted in the show notes selected previously. Let me know if this makes sense!

[tkilgour]

@416serg Thanks for the great feedback! I have updated the show notes section to be blank when the search results are empty. It looked a bit repetitive to add more "not found" text and I don't think it's necessary.

I merged in the latest changes from master and also updated the search field to be position: sticky when there is text entered. Since the show list now scrolls on mobile, it felt necessary to keep it pinned to the top.