Add logo and release date

Author: shaedrich

topics/unist/index.md

@@ -5,5 +5,7 @@ topic: unist
 url: https://unifiedjs.com/
 github_url: https://github.com/syntax-tree/unist
 related: ast, cst, syntax-tree
+released: February 11, 2016
+logo: unist.png
 ---
 unist is a specification for syntax trees. It has a big ecosystem of utilities in JavaScript for working with these trees. It’s implemented by several other specifications.