Read express port from environment

[tawn33y]

From #19

Add functionality to read the server port from process.env

Suggested change from #19:

// startExpressServer.js line 100

// change
const port = options?.port || 3000;

// to
const port = options?.port || process.env.PORT || 3000;

[TEMHITHORPHE]

This looks trivial to support, can I do this??

[tawn33y]

Definitely! 😊