Remove uppercase from admonition titles (#1971)

Author: reakaleek

src/Elastic.Documentation.Site/Assets/markdown/admonition.css

@@ -6,10 +6,6 @@
 			@apply flex items-center gap-3 rounded-t-sm px-4 py-2 font-bold;
 		}
 
-		.admonition-title {
-			@apply text-sm tracking-wider uppercase;
-		}
-
 		.applies-admonition {
 			@apply flex items-center gap-1 font-normal;
 			.applicable-name,