more classic markdown features:

• code blocks
• inline code
• blockquotes
• link titles
• backslash escaping
• setext-style headers

original markdown syntax reference: https://daringfireball.net/projects/markdown/syntax

github-flavored markdown features:

• tables
• task lists
• emoji

ssb markdown features:

• ssb ids (blob ids, msg ids, feed ids) are automatically linkified and abbreviated with '...'
• links to channels ( #tags ) are linkified in recent ssb-markdown
• @feed links where the name is mapped to a feed id in a post's mentions array (can be composed in patchwork-classic or patchfoo)