Update README.asciidoc

README.asciidoc

@@ -30,13 +30,14 @@ We recommend to use Macports or Homebrew to install the required software. Below
 is a recipe for Macports. 
 
 ----
-sudo port install asciidoctor
-sudo port select --set ruby ruby24  # # <1>
+sudo port install asciidoctor       # # <1>
+sudo port select --set ruby ruby24  # # <2>
 sudo port install nodejs12
 sudo gem install asciidoctor-katex
 sudo port install dblatex
 ----
-<1> Select Ruby from Macports as default. Otherwise `/usr/bin/ruby` would be used.
+<1> If not already installed, Ruby will be installed as dependency.
+<2> Select Ruby from Macports as default. Otherwise `/usr/bin/ruby` would be used.
 
 ### Ubuntu 18+
 
@@ -78,6 +79,17 @@ sudo yum install dblatex
 ----
 <1> Installs Asciidoctor as Gem as dependency.
 
+### Redhat Enterprise Linux 8 and clones
+
+----
+sudo yum install nodejs
+sudo gem install asciidoctor-katex # # <1>
+sudo yum --enablerepo=PowerTools install dblatex # # <2>
+----
+
+<1> Install Asciidoctor and KaTeX plugin as Gem.
+<2> The PowerTools repository is **not** enabled by default!
+
 ### openSUSE leap 15.x
 
 > **NOTE:** On openSUSE leap 15 PDF translation does not work out of the box