update subdomain docs

assets/base.scss

@@ -233,7 +233,7 @@ a[href^="./"] {
 
   & #graph-container {
     border: var(--outlinegray) 1px solid;
-    border-radius: 5px
+    border-radius: 5px;
   }
 }
 

content/notes/hosting.md

@@ -39,15 +39,21 @@ Now let's get this site up and running. Never hosted a site before? No problem.
 
 Here, we take advantage of GitHub's free page hosting to deploy our site. Change `baseURL` in `/config.toml`. If you don't have a custom domain to use, you can use `<YOUR-USERNAME>.github.io` (which GitHub gives to you for free!) as your domain.
 
-[Reference.](https://github.com/jackyzha0/quartz/blob/hugo/config.toml)
+[Reference `config.toml` here](https://github.com/jackyzha0/quartz/blob/hugo/config.toml)
 
 ```toml
 baseURL = "https://<YOUR-DOMAIN>/"
 ```
 
+If you are using this under a subdomain (e.g. `<YOUR-GITHUB-USERNAME>.github.io/quartz`), include the trailing path.
+
+```toml
+baseURL = "https://<YOUR-GITHUB-USERNAME>.github.io/quartz/"
+```
+
 Change `cname` in `/.github/workflows/deploy.yaml`. Again, if you don't have a custom domain to use, you can use `<YOUR-USERNAME>.github.io`.
 
-[Reference.](https://github.com/jackyzha0/quartz/blob/hugo/.github/workflows/deploy.yaml)
+[Reference `deploy.yaml` here](https://github.com/jackyzha0/quartz/blob/hugo/.github/workflows/deploy.yaml)
 
 ```yaml
 - name: Deploy  
@@ -82,4 +88,4 @@ Now that your Quartz is live, let's figure out how to make Quartz really *yours*
 
 🎨 [Customizing Quartz](notes/config.md)
 
-Having problems? Checkout our [FAQ and Troubleshooting guide](notes/troubleshooting.md).
+Having problems? Checkout our [FAQ and Troubleshooting guide](notes/troubleshooting.md).