fix: use slugs instead of title as basis for explorer (#652)

* use slugs instead of title as basis for explorer

* fix folder persist state, better default behaviour

* use relative path instead of full path as full path is affected by -d

* dont use title in breadcrumb if it's just index lol

quartz/util/path.ts

@@ -2,7 +2,7 @@ import { slug as slugAnchor } from "github-slugger"
 import type { Element as HastElement } from "hast"
 import rfdc from "rfdc"
 
-const clone = rfdc()
+export const clone = rfdc()
 
 // this file must be isomorphic so it can't use node libs (e.g. path)