Render KaTeX errors in notebooks

Fixes #122413

extensions/notebook-markdown-extensions/notebook/katex.ts

@@ -10,9 +10,17 @@ const link = document.createElement('link');
 link.rel = 'stylesheet';
 link.classList.add('markdown-style');
 link.href = styleHref;
-
 document.head.append(link);
 
+const style = document.createElement('style');
+style.classList.add('markdown-style');
+style.textContent = `
+	.katex-error {
+		color: var(--vscode-editorError-foreground);
+	}
+`;
+document.head.append(style);
+
 const katex = require('@iktakahiro/markdown-it-katex');
 
 export function extendMarkdownIt(md: markdownIt.MarkdownIt) {

extensions/notebook-markdown-extensions/yarn.lock

@@ -4,7 +4,7 @@
 
 "@iktakahiro/markdown-it-katex@https://github.com/mjbvz/markdown-it-katex.git":
   version "4.0.1"
-  resolved "https://github.com/mjbvz/markdown-it-katex.git#e88925a7cb3fd593a14ed117fb43627c4ba910b6"
+  resolved "https://github.com/mjbvz/markdown-it-katex.git#2bf0b89c6c22ef0b585f55ccab66d1f7c5356bea"
   dependencies:
     katex "^0.13.0"