Add a docker dev setup (#3)

Dockerfile

@@ -0,0 +1,26 @@
+FROM alpine:3.9
+
+RUN apk add --no-cache \
+    bash \
+    bash-completion \
+    coreutils \
+    diffutils \
+    findutils \
+    inotify-tools \
+    libxml2-utils \
+    libxslt \
+    make \
+    nodejs \
+    nodejs-npm \
+    procps \
+    python3 \
+    rsync
+
+RUN npm install -g less
+
+RUN mkdir -p /fsfe-local-build/fsfe.org
+
+EXPOSE 8000
+
+CMD sh /fsfe-local-build/docker-cmd.sh
+