'keys' does not handle special keys (like ^J) anymore.
Instead, we should use `key`, which will pass its entire
argument to tmux, without any processing. It is therefore
possible to do something like:
```key ^C```
Or
```key Escape```
Most (if not all) calls to special keys have been
converted to use 'key' instead of 'keys'.
Action ```copypaste``` has been deprecated in favor
of three separate actions:
```copy REGEX``` (searches the regex in the active pane,
and if found, places it in an internal clipboard)
```paste``` (inserts the content of the clipboard as
keystrokes)
```check``` (forces a status check)
Also, a 'tmux' command has been added. It allows to
do stuff like:
```tmux split-pane -v```
In the Kubernetes courses, it takes a bit too long before we
reach the Kubernetes content. Furthermore, learning how to
scale with Compose is not super helpful. These changes
allow to switch between two course flows:
- show how to scale with Compose, then transition to k8s/Swarm
- do not show how to scale with Compose; jump to k8s/Swarm earlier
In the latter case, we still benchmark the speed of rng and
hasher, but we do it on Kuberntes (by running httping on
the ClusterIP of these services).
These changes will also allow to make the whole DaemonSet
section optional, for shorter courses when we want to
simply scale the rng service without telling the bogus
explanation about entropy.
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.
