style: add wmde-markdown-var className.

Author: jaywcjlove

src/styles/markdown.less

@@ -1,5 +1,6 @@
 @media (prefers-color-scheme: dark) {
-  .wmde-markdown {
+  .wmde-markdown,
+  .wmde-markdown-var {
     color-scheme: dark;
     --color-prettylights-syntax-comment: #8b949e;
     --color-prettylights-syntax-constant: #79c0ff;
@@ -47,7 +48,8 @@
 }
 
 @media (prefers-color-scheme: light) {
-  .wmde-markdown {
+  .wmde-markdown,
+  .wmde-markdown-var {
     color-scheme: light;
     --color-prettylights-syntax-comment: #6e7781;
     --color-prettylights-syntax-constant: #0550ae;
@@ -95,6 +97,7 @@
 }
 
 [data-color-mode*='dark'] .wmde-markdown,
+[data-color-mode*='dark'] .wmde-markdown-var,
 body[data-color-mode*='dark'] {
   color-scheme: dark;
   --color-prettylights-syntax-comment: #8b949e;
@@ -142,6 +145,7 @@ body[data-color-mode*='dark'] {
 }
 
 [data-color-mode*='light'] .wmde-markdown,
+[data-color-mode*='light'] .wmde-markdown-var,
 body[data-color-mode*='light'] {
   color-scheme: light;
   --color-prettylights-syntax-comment: #6e7781;