Doc updates to HTTP API

-Rename "REST" API to HTTP API
-Minor documentation for /aql endpoint

Change-Id: I5c6520495752da312f4db7641fcfd14f7d63c829
Reviewed-on: https://asterix-gerrit.ics.uci.edu/331
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Chris Hillery <ceej@lambda.nu>
diff --git a/asterix-doc/src/site/site.xml b/asterix-doc/src/site/site.xml
index 3e81a25..aaa73fc 100644
--- a/asterix-doc/src/site/site.xml
+++ b/asterix-doc/src/site/site.xml
@@ -81,7 +81,7 @@
       <item name="AQL Support of Similarity Queries" href="aql/similarity.html"/>
       <item name="Accessing External Data" href="aql/externaldata.html"/>
       <item name="Filter-Based LSM Index Acceleration" href="aql/filters.html"/>
-      <item name="REST API to AsterixDB" href="api.html"/>
+      <item name="HTTP API to AsterixDB" href="api.html"/>
     </menu>
 
     <menu ref="reports"/>