* docs: update README

This proposes an updated README which is reformatted and also includes a walkthrough to get SAML Jackson up and running quickly.

* changes based on review feedback

* Update .env.example

* Update .env.example with 32 for nextauth

* simplify setup by skipping migrations

* link to README

* clarifying comment

* add line instructing the user to log in using configured credentials

* remove docker line

* README cleanup

* cleanup

* MacOS > macOS

* remove reference to migrations

* typo

* fix grammar

* fix grammar

* updates to README

* update admin portal login options

* fix typos

* tweaks

* small typo fixes

* Update CONTRIBUTING.md

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Co-authored-by: Deepak Prabhakara <[email protected]>