chore(content): improve about

Author: thekaveman

_includes/about.html

@@ -1,17 +1,14 @@
 <p>
-    This is a GitHub Pages <em>organization site</em>, created in a repository named with the pattern
-    <code>org-name.github.io</code>. For Cal-ITP this is
-    <a href="https://github.com/cal-itp/cal-itp.github.io">cal-itp.github.io</a>.
+    This is Cal-ITP's
+    <a href="https://docs.github.com/en/pages/getting-started-with-github-pages/about-github-pages#types-of-github-pages-sites">
+        GitHub Pages organization site</a>, served under a custom domain using a
+        <a href="https://github.com/cal-itp/cal-itp.github.io/blob/main/CNAME">CNAME</a> file.
 </p>
 <p>
-    Like all GitHub Pages sites, organization sites can define a
-    <a href="https://github.com/cal-itp/cal-itp.github.io/blob/main/CNAME"><code>CNAME</code></a> file to customize the domain.
+    This site is the root of Cal-ITP's GitHub Pages project sites, which are the other repositories that have GitHub Pages enabled. These
+    sites are automatically available at <code>https://docs.calitp.org/repo-name</code>.
 </p>
 <p>
-    An organization site serves as the root of that organization's <em>project sites</em>, which are just the other
-    repositories within the organization that have GitHub Pages enabled.
-</p>
-<p>
-    With the custom domain configured here, all Cal-ITP GitHub Pages sites are automatically available at
-    <code>https://docs.calitp.org/repo-name</code>.
-</p>
+    To create a simple Markdown-based documentation site, see our instructions at:
+    <a href="https://docs.calitp.org/mkdocs-template">https://docs.calitp.org/mkdocs-template</a>
+</p>