Fix optional chaining in tag explorer exclude example (#2200)

Prevents null pointer

docs/configuration.md

@@ -36,6 +36,7 @@ This part of the configuration concerns anything that can affect the whole site.
   - `{provider: 'clarity', projectId: '<your-clarity-id-code' }`: use [Microsoft clarity](https://clarity.microsoft.com/). The project id can be found on top of the overview page.
   - `{ provider: 'matomo', siteId: '<your-matomo-id-code', host: 'matomo.example.com' }`: use [Matomo](https://matomo.org/), without protocol.
   - `{ provider: 'vercel' }`: use [Vercel Web Analytics](https://vercel.com/docs/concepts/analytics).
+  - `{ provider: 'rybbit', siteId: 'my-rybbit-id' }` (managed) or `{ provider: 'rybbit', siteId: 'my-rybbit-id', host: 'my-rybbit-domain.com' }` (self-hosted) use [Rybbit](https://rybbit.com);
 - `locale`: used for [[i18n]] and date formatting
 - `baseUrl`: this is used for sitemaps and RSS feeds that require an absolute URL to know where the canonical 'home' of your site lives. This is normally the deployed URL of your site (e.g. `quartz.jzhao.xyz` for this site). Do not include the protocol (i.e. `https://`) or any leading or trailing slashes.
   - This should also include the subpath if you are [[hosting]] on GitHub pages without a custom domain. For example, if my repository is `jackyzha0/quartz`, GitHub pages would deploy to `https://jackyzha0.github.io/quartz` and the `baseUrl` would be `jackyzha0.github.io/quartz`.

docs/features/explorer.md

@@ -162,7 +162,7 @@ You can access the tags of a file by `node.data.tags`.
 Component.Explorer({
   filterFn: (node) => {
     // exclude files with the tag "explorerexclude"
-    return node.data.tags?.includes("explorerexclude") !== true
+    return node.data?.tags?.includes("explorerexclude") !== true
   },
 })
 ```

quartz/cfg.ts

@@ -50,6 +50,11 @@ export type Analytics =
   | {
       provider: "vercel"
     }
+  | {
+      provider: "rybbit"
+      siteId: string
+      host?: string
+    }
 
 export interface GlobalConfiguration {
   pageTitle: string

quartz/plugins/emitters/componentResources.ts

@@ -241,6 +241,16 @@ function addGlobalPageResources(ctx: BuildCtx, componentResources: ComponentReso
       vercelInsightsScript.defer = true
       document.head.appendChild(vercelInsightsScript)
     `)
+  } else if (cfg.analytics?.provider === "rybbit") {
+    componentResources.afterDOMLoaded.push(`
+      const rybbitScript = document.createElement("script");
+      rybbitScript.src = "${cfg.analytics.host ?? "https://app.rybbit.io"}/api/script.js";
+      rybbitScript.setAttribute("data-site-id", "${cfg.analytics.siteId}");
+      rybbitScript.async = true;
+      rybbitScript.defer = true;
+
+      document.head.appendChild(rybbitScript);
+    `)
   }
 
   if (cfg.enableSPA) {