Documentation: Add note about not having sources in repositories

Closes elastic#10390

docs/reference/setup/repositories.asciidoc

@@ -1,12 +1,14 @@
 [[setup-repositories]]
 == Repositories
 
-We also have repositories available for APT and YUM based distributions.
+We also have repositories available for APT and YUM based distributions. Note that we only provide
+binary packages, but no source packages, as the packages are created as part of the Elasticsearch
+build.
 
 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, for 1.1.x use 1.1 etc.
 
-We use the PGP key http://pgp.mit.edu/pks/lookup?op=vindex&search=0xD27D666CD88E42B4[D88E42B4], 
+We use the PGP key http://pgp.mit.edu/pks/lookup?op=vindex&search=0xD27D666CD88E42B4[D88E42B4],
 Elasticsearch Signing Key, with fingerprint
 
     4609 5ACC 8548 582C 1A26 99A9 D27D 666C D88E 42B4
@@ -32,24 +34,24 @@ echo "deb http://packages.elasticsearch.org/elasticsearch/{branch}/debian stable
 
 [WARNING]
 ==================================================
-Use the `echo` method described above to add the Elasticsearch repository.  Do not use `add-apt-repository` 
-as it will add a `deb-src` entry as well, but we do not provide a source package.  
+Use the `echo` method described above to add the Elasticsearch repository.  Do not use `add-apt-repository`
+as it will add a `deb-src` entry as well, but we do not provide a source package.
 If you have added the `deb-src` entry, you will see an error like
 the following:
 
     Unable to find expected entry 'main/source/Sources' in Release file (Wrong sources.list entry or malformed file)
-    
+
 Just delete the `deb-src` entry from the `/etc/apt/sources.list` file and the installation should work as expected.
 ==================================================
 
-Run apt-get update and the repository is ready for use. You can install it with :
+Run apt-get update and the repository is ready for use. You can install it with:
 
 [source,sh]
 --------------------------------------------------
 sudo apt-get update && sudo apt-get install elasticsearch
 --------------------------------------------------
 
-Configure Elasticsearch to automatically start during bootup :
+Configure Elasticsearch to automatically start during bootup:
 
 [source,sh]
 --------------------------------------------------
@@ -59,15 +61,15 @@ sudo update-rc.d elasticsearch defaults 95 10
 [float]
 === YUM
 
-Download and install the Public Signing Key
+Download and install the public signing key:
 
 [source,sh]
 --------------------------------------------------
 rpm --import https://packages.elasticsearch.org/GPG-KEY-elasticsearch
 --------------------------------------------------
 
 Add the following in your `/etc/yum.repos.d/` directory
-in a file named (for example) `elasticsearch.repo`
+in a file with a `.repo` suffix, for example `elasticsearch.repo`
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
@@ -79,22 +81,22 @@ gpgkey=http://packages.elasticsearch.org/GPG-KEY-elasticsearch
 enabled=1
 --------------------------------------------------
 
-And your repository is ready for use. You can install it with :
+And your repository is ready for use. You can install it with:
 
 [source,sh]
 --------------------------------------------------
 yum install elasticsearch
 --------------------------------------------------
 
 Configure Elasticsearch to automatically start during bootup. If your
-distribution is using SysV, then you will need to run :
+distribution is using SysV init, then you will need to run:
 
 [source,sh]
 --------------------------------------------------
 chkconfig --add elasticsearch
 --------------------------------------------------
 
-Otherwise if your distribution is using systemd :
+Otherwise if your distribution is using systemd:
 
 [source,sh]
 --------------------------------------------------