Archive Next CRM against the CRM-xt and Migrator App

[nitun]

As we started using the Frappe CRM, and migrated ERPNext and Next CRM doctypes and fields data to FCRM, we will stop using the Next CRM.

• Update the Next CRM repo and tasks https://github.com/orgs/rtCamp/projects/326. Prepare for the discontinuation of the repo and publish the CRM migrator and CRM-xt app.
• Update the readme
• Documentation/wiki
• Public announcement
• Inform on Discuss community and FCRM repo.