Object Lambda functions to transform objects via a webhook. Expand and
refine the developer docs from
c4d71bc1a5/docs/lambda/README.md
into a new page in the user documentation.
Staged
http://192.241.195.202:9000/staging/DOCS-754/linux/html/developers/transforms-with-object-lambda.html
Notes for reviewers:
In addition to the items noted in inline comments, some general things
to confirm:
* Accurate usage/terminology? Is this how we talk about the relevant
topics?
* Any technical points that need more/more correct detail?
* What would someone need to know to go from trying this dev example to
having a real function in their production environment?
[x] Add new docs page in Developers
[x] Add envars to envar list
Fixes https://github.com/minio/docs/issues/754
