Add documentation about how to create form submissions + a bug

[karirogg]

As of now, one has to dig pretty deep to figure out how to post to the form-submissions endpoint (I had to watch a 15 minute Youtube video that did not fully explain it). There even was no information that you had to post to that endpoint in the docs.

I suggest some information about the endpoint and how it is called is added to the README file in this repository.

I noticed one small bug in form submitting when trying to figure out how to post to the endpoint. If the post request is of the form:

{
    "form": <form-id-here>,
    "submissionData": {}
}

the API creates an empty form submission, even if I have required fields in the form.

Hope this helps!

[jacobsfletch]

This plugin is now being maintained in the Packages Directory of the Payload Monorepo. This repo will soon be archived and all open issues including this one will be closed. This issue has already been added to this open discussion, though, so that it will not get lost. Please refer to that discussion for more details and to continue the conversation.