Edited chapter_09_docker.asciidoc with Atlas code editor

Author: troutman_margaret@yahoo.com

chapter_09_docker.asciidoc

@@ -63,7 +63,7 @@ image::images/tdd3_0901.png["A diagram showing a physical machine, with an opera
 Containerization works at the operating system (OS) level:
 it gives you multiple virtual operating systems that
 all run on a single real OS.footnote:[
-It's more accurate to say that containers share the same kernel as the host OS.((("operating systems (OS)", "containerization at OS level")))
+It's more accurate to say that containers share the same kernel as the host OS.((("operating system (OS), containerization at OS level")))
 An operating system is made up of a kernel,
 and a bunch of utility programs that run on top of it.
 The kernel is the core of the OS;