link-checker: For now only lint cel2 (#1720)

Author: palango

.github/workflows/links.yml

@@ -29,11 +29,7 @@ jobs:
             --verbose
             --no-progress
             --cache --max-cache-age 1d
-            './**/*.html'
-            './**/*.js'
-            './**/*.md'
-            './**/*.rst'
-            './**/*.tsx'
+            './docs/cel2/**/*.html'
         env:
           GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}