From GET to POST requests

[drewg2009]

Hey everyone! Thank you for your contributions so far, I really appreciate it!

In order to support more complex data structures I am going to refactor the existing routes to use POST requests.

If you submit a PR with a GET request, no worries, I will just remind you to refactor to POST once my refactor is pushed

[drewg2009]

All existing routes have been migrated to use POST requests and json payloads. Going forward we will use POST requests for our transformations/validations.

Will let you know if there's a need to balance both, thanks!