fix(docs): scope fenced code language linting (#965)

Author: pimlock

.markdownlint-cli2.jsonc

@@ -23,6 +23,8 @@
     "MD024": { "siblings_only": true },
     // Bare URLs are fine in changelogs and tables.
     "MD034": false,
+    // Internal docs commonly use bare fences for diagrams and terminal sketches.
+    "MD040": false,
     // First line does not need to be a heading.
     "MD002": false,
     // Repo uses padded table pipes (`| foo | bar |`); rule default is "compact".

docs/.markdownlint-cli2.jsonc

@@ -3,6 +3,8 @@
     // MDX pages get their title from Fern frontmatter, not a top-level H1.
     "MD041": false,
     // MDX uses JSX components (<Callout>, <CodeBlock>, ...) that look like HTML.
-    "MD033": false
+    "MD033": false,
+    // Published docs should label fenced code blocks for rendering and copy UX.
+    "MD040": true
   }
 }