add start script

[akash1810]

#18 take 2.

What does this change?

Adds a start script with an option to ignore an already running instance of nginx.

This will be useful when scripting the starting of a service.

Let's say we have the following in the file script/start:

#!/usr/bin/env bash

set -e

sbt run

If the service requires an nginx reverse proxy running, we'd need to separately ensure it's running. This PR allows us to further script nginx, script/start becomes:

#!/usr/bin/env bash

set -e

dev-nginx start -g
sbt run

How can we measure success?

Simplifying the process of starting an application locally.