Update readme

[jkpage00]

Major rewrite of README.md to add legal language and discussion of the intended use of the notebooks, document use of Oauth2 credential and granting ABAC permissions for the credential, etc

Description

• Legal warning included
• Discussion of 2 ways to use the notebooks
  1. Run them in order as a tutorial exercise
  2. Use the notebooks as a template for starting an ML project involving AEP data
• Overview of the notebooks (reflects pending re-organization of notebook content for release, which will be completed in other pull requests)
• Instructions for getting started with the notebooks
  • creating Oauth2 API credentials
  • getting necessary ABAC permissions for the API credential from your Adobe sys admin
  • Updating config.ini with required environment and credential information
  • Configuring aepp with the information from the config.ini in notebook code
  • Testing and troubleshooting the connection to AEP
• Links to helpful resources

Related Issue

Update README with instructions for using Oauth2 credentials and permissions management for the credentials #14

Motivation and Context

Per discussion with legal we needed to include language to warn the user of their responsibility to handle data properly.

We also needed to update the documentation to show usage of Oauth2 credentials, as JWT credentials have been deprecated.

Also added additional guidance per feedback from customers and partners.

How Has This Been Tested?

It's a README, nothing to test.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.