docs: add minimum versions [skip ci]

templates: remove extra line continuation

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

README.md

@@ -31,10 +31,10 @@ alias d2vm='docker run --rm -i -t --privileged -v /var/run/docker.sock:/var/run/
 
 Working and tested:
 
-- [x] Ubuntu
-- [x] Debian
+- [x] Ubuntu (18.04+)
+- [x] Debian (stretch+)
 - [x] Alpine
-- [x] CentOS
+- [x] CentOS (8+)
 
 Unsupported:
 
@@ -194,7 +194,7 @@ applicable law.
 root@localhost:~#
 ```
 
-Type `poweroff` to shutdown the vm.
+Type `poweroff` to shut down the vm.
 
 ### Building a VM Image from a Dockerfile
 

templates/alpine.Dockerfile

@@ -9,16 +9,9 @@ RUN apk update --no-cache && \
       busybox-initscripts \
       openrc
 
-#RUN apk update --no-cache && \
-#    apk add \
-#      linux-virt \
-#      alpine-base \
-#      openssh-server
-
 RUN for s in bootmisc hostname hwclock modules networking swap sysctl urandom syslog; do rc-update add $s boot; done
 RUN for s in devfs dmesg hwdrivers mdev; do rc-update add $s sysinit; done
 
-
 RUN echo "root:{{- if .Password}}{{ .Password}}{{- else}}root{{- end}}" | chpasswd
 
 {{ if eq .NetworkManager "ifupdown"}}

templates/debian.Dockerfile

@@ -31,7 +31,7 @@ network:\n\
         addresses:\n\
         - 8.8.8.8\n\
         - 8.8.4.4\n\
-' > /etc/netplan/00-netcfg.yaml \
+' > /etc/netplan/00-netcfg.yaml
 {{ else if eq .NetworkManager "ifupdown"}}
 RUN apt install -y ifupdown2
 RUN mkdir -p /etc/network && printf '\

templates/ubuntu.Dockerfile

@@ -30,7 +30,7 @@ network:\n\
         addresses:\n\
         - 8.8.8.8\n\
         - 8.8.4.4\n\
-' > /etc/netplan/00-netcfg.yaml \
+' > /etc/netplan/00-netcfg.yaml
 {{ else if eq .NetworkManager "ifupdown"}}
 RUN apt install -y ifupdown-ng
 RUN mkdir -p /etc/network && printf '\