feat: implement breadcrumb component (#508)

* feat: implement breadcrumbs

* style: fix styling, move breadcrumbs to top

* refactor: move `capitalize to `lang.ts``

* refactor: clean breadcrumb generation

* feat: add options to breadcrumbs

* feat: implement `resolveFrontmatterTitle`

* feat: add `hideOnRoot` option

* feat(consistency): capitalize every crumb

* style: add `flex-wrap` to parent container

* refactor: clean `Breadcrumbs.tsx`

* feat(accessibility): use `nav`, add aria label

* style: improve look in popovers by adding margin

* docs: write docs for breadcrumb component

* refactor: collapse `if` condition for hideOnRoot

* chore: add todo for perf optimization

* docs: update introduction

quartz/util/lang.ts

@@ -5,3 +5,7 @@ export function pluralize(count: number, s: string): string {
     return `${count} ${s}s`
   }
 }
+
+export function capitalize(s: string): string {
+  return s.substring(0, 1).toUpperCase() + s.substring(1)
+}