Merge pull request #2753 from jerch/fix_vtfeatures_template

fix missing jekyll header in vtfeatures template

bin/extract_vtfeatures.js

@@ -33,8 +33,15 @@ const TYPES = [
 ];
 
 const MARKDOWN_TMPL = `
+---
+title: Supported Terminal Sequences
+category: API
+---
+
 {::options parse_block_html="true" /}
 
+# Supported Terminal Sequences
+
 xterm.js version: {{version}}
 
 ## Table of Contents