New Standard: NFT metadata - Milestone 2

[yarnauy]

New Standard: NFT metadata - Milestone 2

Description

This PR is for issue #16

• add Cadence code of standard implementation

Submission Links & Documents

Requirements Check

• Have have you met the milestone requirements? Yes
• Have you included tests (if applicable)? No
• Have you met the contribution guidelines of the repos you have submitted code to (if applicable)? Yes
• If this is the last milestone:
  • It's all in the proposal
  • Raye 100%

Other Details

[yarnauy]

Our milestone 1 is here

[kerrywei]

Hello @njuyuanrui , thank you for submitting this! Unfortunately all FLIP FEST PRs need to be submitted before EOD Oct 31 and hence we would have to close this PR.
However, we super welcome you to join our discussions in Dicord, or contribute to our open source projects. Thank you again for participating in the Flow FLIP FEST!