Fixed DNF in acronyms.xml

(Disjoint -> Disjunctive)  Normal Form
See https://wiki.php.net/rfc/dnf_types and https://en.wikipedia.org/wiki/Disjunctive_normal_form

Closes GH-81.

Author: rhertogh

entities/acronyms.xml

@@ -75,7 +75,7 @@
   <varlistentry>
    <term>DNF</term>
    <listitem>
-    <simpara>Disjoint Normal Form</simpara>
+    <simpara>Disjunctive Normal Form</simpara>
    </listitem>
   </varlistentry>
   <varlistentry>