Containerized application and updated README.md file

Closes #14 (closed)

Dockerfile

+# We're taking the latest Alpine version, because it's the smallest
+# and has the least amount of dependencies
+FROM alpine:latest
+
+# Set working directory.
+WORKDIR /app
+
+# Copy the current directory contents (whole project) into the container at /app
+ADD . /app
+
+# Install dependencies
+RUN apk update && \
+    apk add --no-cache nodejs npm && \
+    npm install;
+
+# Run the app
+ENTRYPOINT ["node", "server"]
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