The slides didn't mention to clone the git repo containing
the Compose file for the ELK stack. This is now fixed.
Also, the version numbers were not all correctly set
in this Compose file. Also fixed.
This is a bunch of changes that I had staged, + a few
typo fixes after going through the deck to check its readiness.
There are no deep changes; just a few extra slides
(e.g. about Kata containers and gVisor, and about
services meshes) and typo fixes.
This was discussed and agreed in #246. It will probably break a few
outstanding PRs as well as a few external links but it's for the
better good long term.