Add a specials file for core
Add a specials file for core

Adds a file roughly equivalent to clojure.repl/special-doc-map so that
the documentation generation code can emit docs on specials which don't
exist and don't feature metadata.

See:
 - clojure-grimoire/grimoire#213
 - clojure-grimoire/grimoire#214

clojure-grimoire/lein-grim