Provides command `clojure-essential-ref' to browse the documentation for
symbol in book "Clojure, The Essential Reference".

Works similarly to `cider-clojuredocs-web'.

By default, browse online in a web browser ("liveBook" version) as if
calling explicit command `clojure-essential-ref-web'.

Using sibling package `clojure-essential-ref-nov' one could browse
offline to the ebook version (command `clojure-essential-ref-nov').