docs for new Alpine Linux image

alpine/README-short.txt

@@ -0,0 +1 @@
+A minimal Docker image based on Alpine Linux with a complete package index and only 5 MB in size!

alpine/content.md

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+# What is Alpine Linux?
+
+[Alpine Linux](http://alpinelinux.org/) is a Linux distribution built around [musl libc](http://www.musl-libc.org/) and [BusyBox](http://www.busybox.net/). The image is only 5 MB in size and has access to a [package repository](http://forum.alpinelinux.org/packages) that is much more complete than other BusyBox based images. This makes Alpine Linux a great image base for utilities and even production applications. [Read more about Alpine Linux here](https://www.alpinelinux.org/about/) and you can see how their mantra fits in right at home with Docker images.
+
+%%LOGO%%
+
+# How to use this image
+
+## Usage
+
+Use like you would any other base image:
+
+	FROM alpine:3.1
+	RUN apk add --update mysql-client && rm -rf /var/cache/apk/*
+	ENTRYPOINT ["mysql"]
+
+This example has a virtual image size of only 16 MB. Compare that to our good friend Ubuntu:
+
+	FROM ubuntu:14.04
+	RUN apt-get update \
+		&& apt-get install -y mysql-client \
+		&& rm -rf /var/lib/apt/lists/*
+	ENTRYPOINT ["mysql"]
+
+This yields us a virtual image size of about 232 MB image.
+
+## Documentation
+
+This image is well documented. [Check out the documentation at Viewdocs](http://gliderlabs.viewdocs.io/docker-alpine).

update.sh

@@ -22,6 +22,7 @@ replace_field() {
 
 declare -A otherRepos=(
 	[aerospike]='https://github.com/aerospike/aerospike-server.docker'
+	[alpine]='https://github.com/gliderlabs/docker-alpine'
 	[busybox]='https://github.com/jpetazzo/docker-busybox'
 	[centos]='https://github.com/CentOS/sig-cloud-instance-images'
 	[cirros]='https://github.com/ewindisch/docker-cirros'