feat: search options (#540)

* feat: search options

* feat: sanitize folder names

* fix: add cursor: pointer to switch

* fix: explicitly make the search bar a text input

* refactor: remove magic number

* refactor: extract Switch component to its own file

* refactor: split AppState into multiple files

* refactor: review comments

app/assets/stylesheets/index.css.scss

@@ -1,3 +1,4 @@
+@import "sn-stylekit/dist/stylekit";
 @import "main";
 @import "ui";
 @import "footer";
@@ -11,3 +12,4 @@
 @import "ionicons";
 @import "reach-sub";
 @import "sessions-modal";
+@import "sn";