doc: Move away from el8 or later

doc/sphinx/installation/install_redhat.rst

@@ -13,19 +13,17 @@ Varnish is included in the `EPEL
 incompatible syntax changes in newer versions of Varnish, only older
 versions are available.
 
-We therefore recommend that you install the latest version directly from our repository, as described above.
+We therefore recommend that you install the latest version directly from our
+repository, as described above.
 
 Varnish Cache is packaged in RPMs for easy installation and upgrade on Red Hat
 systems. The Varnish Cache project maintains official packages for the current
-Enterprise Linux versions. Varnish Cache 6.x series are supported on el7 and el8.
+Enterprise Linux versions. Varnish Cache 6.x series are supported on el7.
 
-We try to keep the latest version available as prebuilt RPMs (el7 and el8)
-on `packagecloud.io/varnishcache <https://packagecloud.io/varnishcache/>`_.
+We try to keep the latest version available as prebuilt RPMs on
+`packagecloud.io/varnishcache <https://packagecloud.io/varnishcache/>`_.
 
-Starting with el8 a DNF module will inhibit Varnish packages, and the solution
-is to disable the module before installing::
-
-    dnf module disable varnish
+We no longer provide RPM packages for el8 or later.
 
 Official packages of 6
 ----------------------
@@ -46,6 +44,12 @@ With the release of 6.0.2, users have to switch to switch repositories to get
 the latest version.
 Read more about this on `Release 6.0.2 </releases/rel6.0.2>`_.
 
+We still provide el8 packages for Varnish Cache 6.0 LTS, but so does Red Hat.
+Their el8 package is provided as a DNF module that inhibits our packages, and
+the solution is to disable the module before installing::
+
+    dnf module disable varnish
+
 External packaging
 ------------------
 
@@ -53,6 +57,14 @@ Varnish Cache is also distributed in third party package repositories.
 
 .. _`Fedora EPEL`: https://fedoraproject.org/wiki/EPEL
 
+.. _`Software Collections 2.1`: http://developers.redhat.com/blog/2015/11/17/software-collections-2-1-generally-available/
+
+.. _`provides`: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/8.0_release_notes/rhel-8_0_0_release#BZ-1633338
+
+
 * `Fedora EPEL`_ does community packaging of Varnish Cache.
 
-* RedHat has packaged versions of Varnish Cache available since Software Collections 2.1. Announcement on <http://developers.redhat.com/blog/2015/11/17/software-collections-2-1-generally-available/>.
+* Red Hat has packaged versions of Varnish Cache available since
+  `Software Collections 2.1`_.
+
+* Red Hat provides_ Varnish Cache 6.0 LTS on el8.