and more tweaks

lifted from: https://gist.github.com/dcode/0cfbf2699a1fe9b46ff04c41721dda74#admonitions

README.adoc

@@ -4,6 +4,14 @@
 :toc-placement!:
 :toclevels: 4
 
+ifdef::env-github[]
+:tip-caption: :bulb: Tip
+:note-caption: :information_source: NOTE
+:important-caption: :heavy_exclamation_mark: IMPORTANT
+:caution-caption: :fire: CAUTION
+:warning-caption: :warning: WARNING
+endif::[]
+
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