Simple command line tool using python's grip library and wkhtmltopdf to generate a PDF file from a Markdown file. Basically starts a server, captures it as a PDF and then kills the server (that's the complex bit!)

markdown-to-github-pdf.sh

#!/bin/bash

# Install grip $ pip install grip
# Install wkhtmltopdf $ sudo apt-get install wkhtmltopdf

md=$1
pdf=$md.pdf
port=$(( ( RANDOM % 6000 )  + 5000 ))

echo $port

grip $md localhost:$port &
sleep 10
wkhtmltopdf http://localhost:$port $pdf
kill $(ps -eo pid,command | grep "grip" | grep -v grep | awk '{print $1}')

Run this with

bash markdown-to-github-pdf.sh my-file.md

It will output my-file.md.pdf for you