docker: add block to show running containers and latest container ip

Closes: #168

docker/README.md

@@ -0,0 +1,19 @@
+# docker
+
+Show the number of running `Docker` containers and latest created container IP address.
+
+![](docker.jpg)
+
+# Dependencies
+
+*docker* 
+
+# Config
+
+```
+[docker]
+command=$SCRIPT_DIR/docker
+label=🐳
+color=#0db7ed
+interval=10
+```

docker/docker

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# Number of docker containers running
+count=$(docker ps -q | wc -l | sed -r 's/^0$//g')
+# Recent docker container IP
+recent_ip=$(docker inspect -f "{{ .NetworkSettings.IPAddress }}" $(docker ps -ql))
+
+echo "$count: $recent_ip"

docker/i3blocks.conf

@@ -0,0 +1,5 @@
+[docker]
+command=$SCRIPT_DIR/docker
+label=🐳
+color=#0db7ed
+interval=10