chore: add more markdown tokens to be removed

Author: ulivz

Diff for: lib/util/parseHeaders.js

@@ -11,8 +11,11 @@ const unescapeHtml = html => html
   .replace(/>/g, '>')
 
 const removeMarkdownToken = str => str
-  .replace(/`(.*)`/, '$1')
-  .replace(/\[(.*)\]\(.*\)/, '$1')
+  .replace(/`(.*)`/, '$1')  // ``
+  .replace(/\[(.*)\]\(.*\)/, '$1')  // []()
+  .replace(/\*\*(.*)\*\*/, '$1')  // **
+  .replace(/\*(.*)\*/, '$1')  // *
+  .replace(/_(.*)_/, '$1')  // _
 
 // put here to avoid circular references
 const compose = (...processors) => {