Documentation: Fix rendering of extra repo info for RHEL 8

In commit a82083e ("Documentation: Add extra repo info for RHEL 8")
a newline was missing to correctly generate the code block to add
codeready-builder repository.

This commit adds the missing newline to correctly generate the code block
with the RHEL 8 codeready-builder instructions.

Fixes: a82083e ("Documentation: Add extra repo info for RHEL 8")
Cc: gvrose8192@gmail.com
Signed-off-by: Timothy Redaelli <tredaelli@redhat.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>

Documentation/intro/install/fedora.rst

@@ -70,6 +70,7 @@ repositories to help yum-builddep, e.g.::
     $ subscription-manager repos --enable=rhel-7-server-optional-rpms
 
 or for RHEL 8::
+
     $ subscription-manager repos \
       --enable=codeready-builder-for-rhel-8-x86_64-rpms