front-matter must be delimited by ---

browser/lib/markdown-it-frontmatter.js

@@ -0,0 +1,21 @@
+'use strict'
+
+module.exports = function frontMatterPlugin (md) {
+  function frontmatter (state, startLine, endLine, silent) {
+    if (startLine !== 0 || state.src.substr(startLine, state.eMarks[0]) !== '---') {
+      return false
+    }
+
+    let line = 0
+    while (++line < state.lineMax && state.src.substring(state.bMarks[line], state.eMarks[line]) !== '---') {
+    }
+
+    state.line = line + 1
+
+    return true
+  }
+
+  md.block.ruler.before('table', 'frontmatter', frontmatter, {
+    alt: [ 'paragraph', 'reference', 'blockquote', 'list' ]
+  })
+}