fix(prism-theme): fix typo .toke.variable -> .token.variable

The CSS selector for Prism variable tokens was misspelled as .toke.variable
instead of .token.variable. This caused variable tokens (bash $VARIABLES,
CSS custom properties, template literals, etc.) to never receive the intended
color (#a9becc) in syntax-highlighted code blocks across all documentation
pages.

Author: ryzrr

src/components/Markdown/prism-theme.scss

@@ -82,7 +82,7 @@ pre[class*="lang-"] {
 .token.entity,
 .token.url,
 .language-css .token.string,
-.toke.variable {
+.token.variable {
   color: #a9becc;
 }