Remove keyword restriction re . in keywords, see CLJ-889

Author: puredanger

content/reference/reader.adoc

@@ -41,7 +41,6 @@ Since we have to start somewhere, this reference starts where evaluation starts,
 * Symbolic values - `pass:[##Inf]`, `pass:[##-Inf]`, and `pass:[##NaN]`
 * Keywords - Keywords are like symbols, except:
 ** They can and must begin with a colon, e.g. :fred.
-** They cannot contain '.' in the name part, or name classes.
 ** Like symbols, they can contain a namespace, `:person/name`, which may contain '.'s.
 ** A keyword that begins with two colons is auto-resolved in the current namespace to a qualified keyword:
 *** If the keyword is unqualified, the namespace will be the current namespace. In `user`, `::rect` is read as `:user/rect`.