nested tag support and tag index page

quartz/plugins/emitters/componentResources.ts

@@ -160,7 +160,7 @@ export const ComponentResources: QuartzEmitterPlugin<Options> = (opts?: Partial<
           content: transform({
             filename: "index.css",
             code: Buffer.from(stylesheet),
-            minify: true
+            minify: true,
           }).code.toString(),
         }),
         emit({

quartz/plugins/emitters/tagPage.tsx

@@ -5,7 +5,13 @@ import BodyConstructor from "../../components/Body"
 import { pageResources, renderPage } from "../../components/renderPage"
 import { ProcessedContent, defaultProcessedContent } from "../vfile"
 import { FullPageLayout } from "../../cfg"
-import { CanonicalSlug, FilePath, ServerSlug, joinSegments } from "../../path"
+import {
+  CanonicalSlug,
+  FilePath,
+  ServerSlug,
+  getAllSegmentPrefixes,
+  joinSegments,
+} from "../../path"
 
 export const TagPage: QuartzEmitterPlugin<FullPageLayout> = (opts) => {
   if (!opts) {
@@ -26,15 +32,23 @@ export const TagPage: QuartzEmitterPlugin<FullPageLayout> = (opts) => {
       const allFiles = content.map((c) => c[1].data)
       const cfg = ctx.cfg.configuration
 
-      const tags: Set<string> = new Set(allFiles.flatMap((data) => data.frontmatter?.tags ?? []))
+      const tags: Set<string> = new Set(
+        allFiles.flatMap((data) => data.frontmatter?.tags ?? []).flatMap(getAllSegmentPrefixes),
+      )
+      // add base tag
+      tags.add("")
+
       const tagDescriptions: Record<string, ProcessedContent> = Object.fromEntries(
-        [...tags].map((tag) => [
-          tag,
-          defaultProcessedContent({
-            slug: `tags/${tag}/index` as ServerSlug,
-            frontmatter: { title: `Tag: ${tag}`, tags: [] },
-          }),
-        ]),
+        [...tags].map((tag) => {
+          const title = tag === "" ? "Tag Index" : `Tag: #${tag}`
+          return [
+            tag,
+            defaultProcessedContent({
+              slug: joinSegments("tags", tag, "index") as ServerSlug,
+              frontmatter: { title, tags: [] },
+            }),
+          ]
+        }),
       )
 
       for (const [tree, file] of content) {
@@ -48,7 +62,7 @@ export const TagPage: QuartzEmitterPlugin<FullPageLayout> = (opts) => {
       }
 
       for (const tag of tags) {
-        const slug = `tags/${tag}/index` as CanonicalSlug
+        const slug = joinSegments("tags", tag) as CanonicalSlug
         const externalResources = pageResources(slug, resources)
         const [tree, file] = tagDescriptions[tag]
         const componentData: QuartzComponentProps = {