Add project: W3BA Escrow Milestones Contract

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Built with Rust and CosmWasm.

Includes

• Unit and integration tests
• Demo video

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Link to repo: https://github.com/Web3-Builders-Alliance/CosmWatch-CosmWasm-Q1-2023/tree/main/Capstone/cw20-milestone-escrow

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Link to demo video: https://www.youtube.com/watch?v=lzwMiCIeUDo