[DOCS] Use index-all.asciidoc for Elasticsearch Reference (#195)

* [DOCS] Use index-all.asciidoc for Elasticsearch Reference

* [DOCS] Add X-Pack repo to Elasticsearch Reference

Author: lcawl

conf.yaml

@@ -51,7 +51,7 @@ contents:
             prefix:     en/elasticsearch/reference
             current:    5.4
             branches:   [ { master: 6.0.0-alpha2 }, 5.x, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
-            index:      docs/reference/index.asciidoc
+            index:      docs/reference/index-all.asciidoc
             chunk:      1
             tags:       Elasticsearch/Reference
             sources:
@@ -74,10 +74,11 @@ contents:
                 repo:   elasticsearch
                 path:   docs/painless
                 exclude_branches:   [ 5.x, 5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
-#              -
-#                repo:   x-pack-elasticsearch
-#                path:   docs/public
-#                exclude_branches: [ 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
+              -
+                repo:   x-pack-elasticsearch
+                prefix: elasticsearch-extra/x-pack-elasticsearch
+                path:   docs/en
+                exclude_branches: [5.4, 5.3, 5.2, 5.1, 5.0, 2.4, 2.3, 2.2, 2.1, 2.0, 1.7, 1.6, 1.5, 1.4, 1.3, 0.90 ]
 
           -
             title:      Elasticsearch - The Definitive Guide