Expand the CCTP page with a guide for Stellar-as-source transfers #2873

/docs/tokens/cross-chain-transfers says CCTP supports Stellar and links to Circle. Builders want to bridge native USDC from Stellar to EVM chains automatically with one user signature, and get stuck on two Stellar-specific points Circle's docs don't cover: the CCTP contracts call transfer_from, so single-signature flows need a wrapper contract or a pre-existing allowance on the USDC SAC; and whether to run your own attestation relayer or use a third party.

Please expand the page with:

• the burn → attestation → mint flow from Stellar, including the allowance/wrapper requirement;
• relayer options and tradeoffs;
• a worked example. https://github.com/ElliotFriend/stellar-cctp-demo covers part of this.

Surfaced by Frontier Lab's ecosystem crawl.