Added extension options:
- Specify frontmatter and backmatter (text that will be appended to the start/end of the markdown)
- You can substitute variables (surrounded by curly braces) into these templates. See the options page for instructions
- This includes a {date:FORMAT} option, so you can include the current date in the template
- Specify the various turndown options for converting the HTML to markdown
- For example, you can change the way headers are formatted, have code blocks fenced instead of indented, etc.