fix(html): resolve validation errors, implement dynamic MDX heading shifting, and improve accessibility

test-html.js

@@ -0,0 +1,16 @@
+const fs = require('fs');
+const html = fs.readFileSync('.htmlvalidate-tmp/page-8.html', 'utf8');
+console.log('--- MAIN TAGS ---');
+const mainTags = html.match(/<main[^>]*>/g);
+console.log(mainTags);
+
+console.log('--- DUP CLASS EXAMPLES ---');
+const classAttr = html.match(/class="[^"]*text-slate-500[^"]*"/g);
+if (classAttr) {
+  console.log(classAttr[0]);
+}
+
+const dupText10 = html.match(/class="[^"]*text-\[10px\][^"]*"/g);
+if (dupText10) {
+  console.log(dupText10[0]);
+}