refactor(Markdown): use Tailwind text scale for heading sizes

Author: sujalgoel

src/components/Markdown/Markdown.css

@@ -15,22 +15,22 @@
   @apply leading-normal;
 
   h1 {
-    @apply text-[33.178px];
+    @apply text-4xl;
   }
   h2 {
-    @apply text-[27.648px];
+    @apply text-3xl;
   }
   h3 {
-    @apply text-[23.04px];
+    @apply text-2xl;
   }
   h4 {
-    @apply text-[19.2px];
+    @apply text-xl;
   }
   h5 {
     @apply text-base;
   }
   h6 {
-    @apply text-[13.331px];
+    @apply text-sm;
   }
 
   h2,