web: Fix inline documentation rendering (#13379)

web: Fix issues surrounding markdown rendering.

- Fix issue where Mermaid diagrams do not render.
- Fix link colors in dark mode.
- Fix anchored links triggering router.
- Fix issue where links occasionally link to missing page.

web/src/global.d.ts

@@ -1,15 +1,19 @@
 declare module "*.css";
 
 declare module "*.md" {
+    /**
+     * The HTML content of the markdown file.
+     */
     const html: string;
-    const metadata: { [key: string]: string };
-    const filename: string;
+    export default html;
 }
 
 declare module "*.mdx" {
+    /**
+     * The HTML content of the markdown file.
+     */
     const html: string;
-    const metadata: { [key: string]: string };
-    const filename: string;
+    export default html;
 }
 
 declare namespace Intl {