feat(styles): add background to code block title (#4323)

Co-authored-by: Brandy Smith <6577830+brandyscarney@users.noreply.github.com>

Author: brandyscarney

src/styles/components/_code.scss

@@ -51,6 +51,8 @@ code {
 // Overrides
 #__docusaurus {
   [class*='codeBlockContainer_'] {
+    --prism-background-color: var(--code-block-bg-c);
+
     box-shadow: none;
   }
 }
@@ -63,7 +65,6 @@ code {
 
 code[class*='language-'],
 pre[class*='language-'] {
-  background: var(--code-block-bg-c);
   white-space: pre;
   word-spacing: normal;
   word-break: normal;