NFT as an account (NFTAA) (#2396)

* nftaa init

* Update nftaa.md

* Update nftaa.md

fix table, delete eth addr

* Update nftaa.md

Add 0 requirements to milestones 2 and 3

* Replace developing custom apps with integration for existing ones in milestones

* Update nftaa.md

* Update nftaa.md

Author: Roman-24