Define arg alias and boolean types.

[swim]

Hello,

Motivation: Without defining which args are boolean the endpoint url can accidentally be picked up as a value.

Example: node dist/index.js -j http://sym-graphql.docker.local/graphql > symfony.json

Solution: Define the boolean types; and alias to keep it tidy.

Thanks for a wonderful library, really helpful for debugging schemas / stitching.

[ThisIsMissEm]

Does this then change later code where we read from both argv['j'] and argv['json']? Do we only need to read from argv['json'] after this change?