Fix A a typo

Author: azaroth42

common/terms.html

@@ -80,7 +80,7 @@
     of expressing an <a>IRI</a> without needing to define separate <a>term</a> definitions for
     each IRI contained within a common vocabulary identified by <a>prefix</a>.</dd>
   <dt><dfn data-lt="contexts">context</dfn></dt><dd>
-    A a set of rules for interpreting a <a>JSON-LD document</a> as specified in
+    A set of rules for interpreting a <a>JSON-LD document</a> as specified in
     <a data-cite="JSON-LD11#the-context">The Context</a> of the JSON-LD Syntax specification [[JSON-LD11]].</dd>
   <dt><dfn>datatype IRI</dfn></dt><dd>
     A <a data-cite="RDF11-CONCEPTS#dfn-datatype-iri" class="externalDFN">datatype IRI</a>