📕 Add documentation for Parse.Cloud.afterFind

[nangyal]

Link to section:
https://github.com/parse-community/parse-server/blob/master/src/cloud-code/Parse.Cloud.js#L275

What is the issue?
Parse.Cloud.afterFind not documented

Can you propose a solution?

[TomWFox]

Thanks for bringing that up, would you be willing to make a PR for this?