Add repository information to docs

This adds the apt and yum repo information to the setup docs.

docs/reference/setup.asciidoc

@@ -57,3 +57,4 @@ include::setup/as-a-service-win.asciidoc[]
 
 include::setup/dir-layout.asciidoc[]
 
+include::setup/repositories.asciidoc[]

docs/reference/setup/repositories.asciidoc

@@ -0,0 +1,50 @@
+[[setup-repositories]]
+== Repositories
+
+We also have repositories available for APT and YUM based distributions.
+
+We have split the major versions in separate urls to avoid accidental upgrades across major version.
+For all 0.90.x releases use 0.90 as version number, for 1.0.x use 1.0, etc.
+
+=== APT
+
+Download and install the Public Signing Key
+
+[source,sh]
+--------------------------------------------------
+wget -O - http://packages.elasticsearch.org/GPG-KEY-elasticsearch | apt-key add -
+--------------------------------------------------
+
+Add the following to your /etc/apt/sources.list to enable the repository
+
+[source,sh]
+--------------------------------------------------
+deb http://packages.elasticsearch.org/elasticsearch/0.90/debian stable main
+--------------------------------------------------
+
+Run apt-get update and the repository is ready for use.
+
+
+=== YUM
+
+Download and install the Public Signing Key
+
+[source,sh]
+--------------------------------------------------
+rpm --import http://packages.elasticsearch.org/GPG-KEY-elasticsearch
+--------------------------------------------------
+
+Add the following in your /etc/yum.repos.d/ directory
+
+[source,sh]
+--------------------------------------------------
+[elasticsearch-0.90]
+name=Elasticsearch repository for 0.90.x packages
+baseurl=http://packages.elasticsearch.org/elasticsearch/0.90/centos
+gpgcheck=1
+gpgkey=http://packages.elasticsearch.org/GPG-KEY-elasticsearch
+enabled=1
+--------------------------------------------------
+
+And your repository is ready for use.
+