update theme definitions table structure, styles, and data

Author: danabauer

docs/guides/index.mdx

@@ -1,7 +1,21 @@
 ---
+id: index
+slug: /guides/
 title: Data Guides
+sidebar_label: Overview
+description: Overture Maps data theme documentation
 ---
 
 import DocCardList from '@theme/DocCardList';
 
-<DocCardList />
+## Theme Definitions
+
+<div style={{textAlign: 'center', marginBottom: '2rem'}}>
+  <a href="/theme-definitions-table.html" className="button button--primary button--lg">
+    View Theme Definitions Table →
+  </a>
+</div>
+
+## Theme Guides
+
+<DocCardList />

docs/guides/theme-definitions.mdx

@@ -57,7 +57,6 @@ const sidebars = {
       },
       collapsed: true,
       items: [
-        'guides/theme-definitions',
         'guides/addresses',
         'guides/base',
         'guides/buildings',