Fixed some typos and consistency in spacing. (rancher#639)

Fixed some warnings reported by the Markdown linter (https://github.com/DavidAnson/markdownlint/blob/main/doc/Rules.md).

k3s: bump to v1.19.4+k3s1 (rancher#615)

base: add xfsprogs (rancher#596)

Add wpa_supplicant explicitly (rancher#594)

Previously, wpa_supplicant was install implicitly as a dependency of
connman. In alpine 3.12 it is no longer a depedency and needs to be
added seperately.

k3s: avoid over-quoting install envvars (rancher#590)

Fix K3S_URL, K3S_TOKEN, and K3S_CLUSTER_SECRET being passed to k3s
install.sh with extra quotes around the values. Rely on k3s install.sh
to correctly capture entries for `/etc/k3s/k3s-service.env`.

Fixes rancher#589

k3s: v1.19.2+k3s1 (rancher#587)

k3s: v1.19.2+k3s1 (rancher#587)

kernel: 5.4.0-48.52-rancher1 (rancher#586)

mount from bare usb device if mount fails

If mounting the discovered USB device fails during install, try again mounting the bare device, i.e. /dev/sdb3 -> /dev/sdb.

mount from bare usb device if mount fails

If mounting the discovered USB device fails during install, try again mounting the bare device, i.e. /dev/sdb3 -> /dev/sdb.