Usage
1 hour 20 minutes in milliseconds
const ms = require('@maxdome/parse-duration')('1h 20m');
1 hour 20 minutes in seconds (with second parameter)
const s = require('@maxdome/parse-duration')('1h 20m', 's');
1 hour 20 minutes in seconds (with "in" keyword)
const s = require('@maxdome/parse-duration')('1h 20m in s');